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2026

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2023

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2022

Properly fitting Problems

4 minute read

What motivated this essay was two posts I recently saw. The first started with the idea that no student should take more than five minutes on a problem. If…

15-75-90 on the quarter circle

less than 1 minute read

I just saw a nice visual proof of the ratios for the 15-75-90 on the internet via @ilarrosac.   This one works via symmetry and the Pythagorean theorem. 

Two Circumcircles Walkthrough

2 minute read

I really enjoyed working through this problem from Stanley Rabinowitz I saw recently on Twitter. This was one of those problems where I circled around it a...

Cyclic Quad Area Problem

5 minute read

What follows is a walkthrough of the problem above which I had a lot of fun playing around with. Most of the solutions I saw online used trigonometry and so…

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2021

AP PreCalculus?

4 minute read

I read a really interesting post by David Bressound  on joining the advisory board for AP PreCalculus: link.  The gist of which was despite misgivings he tho...

Sine Hunt

less than 1 minute read

Sine HuntThis is a working post to collect problems themed around sine.  It all started during the last MathJam when a few came up: Criteria:  only sine and ...

Trig Cheat Sheet Project

less than 1 minute read

A few months ago, I saw a thread about writing a trigonometry cheat sheet for someone studying Pre-Calculus.  I decided that I wanted to do a visual version ...

Facilitating a Virtual Math Circle

6 minute read

This year I haven’t written much about how my Math Circle is doing. That doesn’t mean it hasn’t been running the whole time.  My routines were shaken by ...

Pascal’s Determinant

5 minute read

Tamas Gorbe posted the preceding tweet a few days ago and it caught my attention for two reasons. First, I’ve been doing a lot of linear algebra recently…

3x3 Determinant

3 minute read

There are definitely more general and less messy ways to derive the 3x3 matrix determinant (breaking it apart using the linearity property and finding the ...

Roots of Unity Application

3 minute read

Show that $ \sin\left(\dfrac{\pi}{n}\right)  \cdot \sin\left(\dfrac{2\pi}{n}\right)  …   \sin\left(\dfrac{(n-1)\pi}{n}\right)   =  \dfrac{n}{2^{n-1}} $...

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2020

Pushing the limits

less than 1 minute read

I’m still playing around with the ideas from going-one-step-beyond-herons-formula   And this time I looked at a more complex problem.  Overall the approach l...

More Heron’s Formula Extensions

2 minute read

Continuing on the theme from the last post: going-one-step-beyond-herons-formula  here’s another problem showing the power of the full conceptual framework...

11/3 Math in the time of Covid

3 minute read

It took nearly a month longer than normal but I finally have the virtual math club setup for the year and we met for the first time on Tuesday.  Given the w...

Fantasy High School Part 4 PreCalc

2 minute read

I’ve been looking around at sample curriculum sequences due to odd  seeming topics I’ve seen at home via the Pre-Calculus class my older son is taking,  In t...

Ratios vs determinants

1 minute read

Today’s post regards a small conceptual improvement.  It all started with the following problem which caused some trouble for the kids:

What I like about Algebra 2

3 minute read

I worry about Algebra 2 from time to time. Its the class that is mostly likely to be target for reform, usually complete replacement. But  my older son is cu...

Pershan Geometry Walkthrough #2

3 minute read

This is the continuation of a series from First Post  I’m following Michael along and capturing my problem solving process for comparison. To capture the pro...

Everything is Connected (yet again)

3 minute read

The other week I was checking out the geometric puzzles at https://sciencevsmagic.net/geo/ as part of a MathsJam evening.  A small part of the process requir...

2/24 Moems #3

1 minute read

We spent another week catching up on MOEMS tests. This unfortunately doesn’t make for exciting write ups because I’m not supposed to directly discuss the que...

2/11 Quick Catchup

less than 1 minute read

I’m a bit behind on my session logging so what follows is an abbreviated account.

Deep Dive on a Problem

4 minute read

Once again the Math Circle didn’t meet this time due to MLK Day rather than snow.  In fact, next week, I have an offsite at work which is going to interfere ...

1/9 New Year Math

2 minute read

Another new year, another chance to do some math around it! I saved a group of posts off of twitter but ended up leaning the most on a post on Math Misery by...

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2019

12/9 Closing out 2019 with a bang

2 minute read

I knew after last week I wanted to do a game this time around to balance things out but I wasn’t quite sure which one to pick. So  I looked around a few sites…

Trig Angle Addition Two Ways

1 minute read

I’m really enjoying contrasting these two approach right now to deriving the since and cosine angle addition formulas. Just like in the normal pedagogy for t...

12/3 Geometry while Randomized

3 minute read

This week I had a bit of a change of heart while in the middle of my planning process. Originally I was attracted to a triangle inequality problem  and start...

11/25 First MOEMS

3 minute read

(Half of the room that fit in my camera focus hard at work) Randomization  (VRG) I once again moved the kids around into semi-random seating. Partly…

11/18 Connecting all the dots

3 minute read

Interestingly the teacher I share the room with mentioned that it was a hard day for her and I also had more trouble than I like getting everyone to listen t...

10/28 Halloween

1 minute read

Planning-wise my weekend was busier than expected so I decided to go with an easier to setup problem carnival structure for this week: roughly themed around ...

10/21 Sharing is Caring

2 minute read

The overarching personal theme for this week is I’m starting to feel more comfortable with the large size of the group.  So far  I’m able to keep things flow...

Fooling Around

3 minute read

I came across the following interesting piece of Algebra in my son’s textbook.  Solve for  a and b $ \in \mathbb{R}$:

NWMC ‘19 Post Conference Thoughts

4 minute read

Once again, I went and spoke at the NWMC conference. This year it was conveniently located down in Tacoma.  That meant, no hotel or extended travel. Instead ...

10/7 Once more into the breach

4 minute read

Math Club for this year is finally up and running.  As I’ve alluded to before, there are 28 kids which is by far the largest group I’ve ever led.  So I’ve be...

Heron’s Formula vs Trigonometry

4 minute read

This random pedagogical thought occurred to me today: Both  Heron’s Formula and the Law of Cosines provide ways to find the area of a triangle with just its ...

Variance Formulas

5 minute read

I’ve been dabbling in Statistics to help my older son out who has encountered them for the first time in a Biology Class. As a result, an interesting observa...

An Update on Setting Things Up

1 minute read

An Update on Setting  Things Up I’ve stayed fairly on top of things this year.  School started on Wed. The first PTSA newsletter went out with the Math…

15-75-90 Alternate Forms

2 minute read

Its been a while since I’ve talked about one of my favorite triangles the 15-75-90. So here’s a short post on a new detail that I realized about them the oth...

Cardano’s Method

5 minute read

This all starts with a fantastic new video from Mathologer: 500 years of NOT teaching the cubic formula.

Angle Pairs

less than 1 minute read

Visual proof that $ \angle{BCA} + \angle{DCE} = \pi / 4 $ or alternatively $ \arctan \left( \dfrac{u-v}{u+v} \right) + \arctan \left(\dfrac{v}{u}\right) = \p...

2018-2019 Year In Review

4 minute read

This is a bit delayed but better late than never. My overall experience this year was definitely a continuation of last year: (See: 2018-year-in-review)

6/21 Last Day

less than 1 minute read

This post was a bit delayed by  my chaotic schedule right. I’ve decided to dash it out now before the details fade too much more. As is traditional I brought…

6/10 Penultimate Session

2 minute read

The year is winding down and the weather is ramping up. We’re having a mini heat wave in Seattle and the room today was stuffy and warm today. My plan for ne...

6/3 Tesselations

2 minute read

I skipped blogging last week given a hectic schedule and the fact I had outlined my plan already here: 513-checkers-redux  but I’m still thinking over one pa...

Langley’s Adventitious Angles

4 minute read

I’ve been working through “Geometry Revisited” and have come to a section of old chestnuts one of which was Langley’s Adventitous Angles.

5/13 Checkers Redux

3 minute read

I have a lot of chess players in Math Club this year and partly based on that interest and partly because I happened on a James Grimes video I decided I want...

5/6 Purple Comet Day - VRG

4 minute read

Where we last left off:  The Purple Comet math contest wasn’t well aligned this year with our schedule. It ran from  Tue - Fri over a period of time that onl...

4/29 Prepping for STEAM Night

1 minute read

Its crunch time this week getting ready for STEAM night, basically the Science Fair, on Wednesday.  The kids had voted last week to ambitiously attempt three...

Good Problem but Guessable

3 minute read

Last week as usual I scanned through the Purple Comet problems looking for interesting one this year.  I’m usually drawn to geometry problems but this Algebr...

4/1 I put a Hex on You

3 minute read

In the lead up to this week I had been debating whether to participate in the https://purplecomet.org/ contest. The start was a little too close to when we h...

3/25 Guest Lecture on Apportionment

1 minute read

As is now a 3 year running tradition today we had a guest lecturer from the WXML group at UW. This time Jonah Ostroff was kind enough to come a talk with the...

3/4 A series of interludes

2 minute read

As I previously mentioned I’ve been collecting a group of mathematical issues I want to discuss with the kids. So today rather than a large overarching  them...

Julia Robinson Festival

1 minute read

The Julia Robinson Festival is my favorite volunteer activity of the year.  Here we’re setting up all the tables and just getting ready for ~500 kids from…

2/25 So Little Time

2 minute read

The theme for this week was definitely time pressure. After losing 2 weeks to snow days and another one to the mid-winter break I’m feeling behind. The most…

1/28 MOEMS #3 and Posters

1 minute read

Scheduling has been tight very tight this winter.  Because last Monday was off for MLK day, this is only our third session so far. The last two weeks were bo...

Trig Walk Throughs

3 minute read

I’m in the process of writing a bigger piece on the role of trig formulas but I was looking for an example of their use during a geometry proof and came to t...

1/14 Randomness

3 minute read

Going into today I wanted to do something interesting and non-competitive especially for the new kids who just joined. I have  MOEMS test I need to do in the...

1/8 Semi Prime kind of Life

3 minute read

Everyone’s finally back from Winter Break and as you can see from the out take above in good spirits.  If you’ve been following along you might also notice t...

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2018

Countdown to 2019

2 minute read

This is a  collated version of the series of tweets I put out over the last week or so.  I had a fun time reminiscing about all the mathematics I liked over ...

12/17 Game Day

less than 1 minute read

I decided to do a photo diary for Game Day today which was a mixture of my familiar old favorites and a special packet of coloring pages from Edmund Harriss

12/10 MOEMS Olympiad #2

1 minute read

I always enjoy Olympiad days even if I’m not allowed to explicitly discuss the problems because of the white boarding opportunities they afford.   There are…

Some notes on this year ‘s AMC 8

6 minute read

Now that the AMC problems have been publicly released: Link to 2018 set  I thought it would be fun to discuss a few from the last five.  Before starting I al...

Revisiting the 15-75-90

2 minute read

[This is an old post I kept around which seems appropriate to publish today before AMC 8 (which unfortunately makes for poor blogging fodder)]

11/5 First MOEMS Day

1 minute read

I went back and forth on what to do today. Initially I had been thinking about exploring truchet tiles. I’ve found some starter points on chalkdust but the q...

Everything old is new again

2 minute read

This will be a short post but I’m excited enough to write this all down. Yesterday I had one of those moments where you go through a range of feelings. It al...

10/22 Recursive Art

1 minute read

Since I’m behind blogging: this is a bit of an abbreviated summary of the last session. I decided I wanted to do some of the art projects from Clarissa Grand...

NWMath Reflections

6 minute read

This weekend I returned from the Northwest Math Conference in Whistler. Overall I had a blast. If one were to sum it up, the whole event was an exercise in…

10/8 Euclid’s Algorithm

4 minute read

Today the four kids who were not present the first time all came so I decided to start with everyone reintroducing themselves to the group.  I had a few kids...

10/1 Year 5!

5 minute read

This is my fifth year doing a math club and its still just as thrilling to start again as it was the first time. (Although a lot less nerve wracking now that...

Getting Back into Gear

3 minute read

Never put off till to-morrow what you can do day after to-morrow just as well.—B. F   “Mark Twain falsely attributing a quote to Benjamin Franklin” Its that ...

Vieta Formula Brainstorming

3 minute read

I’ve on and off thought a bit about Vieta’s Formulas over the last few years.  The AoPS Algebra textbook introduces them and has a few beginner problems. The...

Forward to sender

less than 1 minute read

This week I had been thinking of writing about the Big Internet Math Off but instead was invited to write about it on aperiodical.com itself. So go to https:...

Fantasy High School

4 minute read

@carloliwitter was tweeting recently about re-imagining High School mathematics and asking for ideas. The topic has caught my fancy even though its a bit off...

More connections

2 minute read

I’ve been thinking alot about polynomial deltas recently. See: polynomial-differences.  It turns out, that there are a variety of problems where its fun to u...

6/5 Woven Math

1 minute read

I’ve been wanting to do this math/art project since I first saw Allison’s artwork on twitter. I finally had enough time to practice and find the supplies.  O...

5/29 Phi Day

2 minute read

This week I wanted to extend some of our talk about the golden ratio. For the last reference see:  515-chaos-mod-arithmetic   I’m also not quite done testing...

Exponent Tower Redux

7 minute read

I saw a different version of the tower of 7’s problem in a book I’m reading on number theory. This is the mostly rambling thought process I’ve been going thr...

Tangles and Symmetry

2 minute read

This is a description of Dr. David Pengelley’s talk “All Tangled up and Searching for the Beauty of Symmetry” which I just attended. This makes an excellen...

5/9 Square Roots

3 minute read

Today I returned to a topic, square roots, I’ve done before with younger kids : 53-square-roots.  My thinking was that I had a cool video I wanted to show th...

5/2 Following my passion

3 minute read

This week I ended up switching my focus on the fly. I had been originally been planning on doing a graph theory math circle  activity centered around chicken...

4/16 Purple Comet Online Contest

7 minute read

Three years ago I discovered the Purple Comet contest @ purplecomet.org.  It has close links to the AwesomeMath  and I really liked the problems in the old t...

4/3 Spring is Sprung

3 minute read

The last few weeks I’ve been concentrating on arranging the topics up to the last MOEMS Olympiad. This week I looked forward enough to realize that first Spr...

3/20 Visible Math

4 minute read

This week started with a walk through of the MathCounts problem that I gave out last week to do at home.

3/13 Pi Day - 1

4 minute read

This is my fourth experience with Pi Day or “Pi Day - 1” as I called it since we meet on Tuesdays.

Carnival of Mathematics 155

4 minute read

Welcome to the 155th Carnival of Mathematics which collects a sampling of interesting math(s) related posts from around the web. This is my first time hostin...

Aloha

less than 1 minute read

I’m on mid winter break with the kids for the week in Oahu. In the meantime check out my collected problems which are almost at 30 in total: [http://mymathcl...

2/6 Olympiad #3 and AMC 10

3 minute read

I almost cancelled this week’s math club due to feeling ill the night before. But in the end I was well enough and the activities were straightforward so I w...

1/30 Math Counts Prep Day

3 minute read

We’re only two weeks out from MathCounts and I’ve been so busy with various topics and activities  that I haven’t really specifically focused on it. For the ...

1/20 Fold and Cut II

2 minute read

Today started with an interesting whiteboard demo for the Problem of the Week.  This is a fairly straight forward combinatorics problem on a small 2^9 total ...

Fun with Pentagons

2 minute read

I’m in the mood for a geometry walk-through. I’ll start out by saying this one has tons of solutions. I’ve thought of 3 or 4 and seen several additional ones...

1/2 Math for a New Year (2018)

4 minute read

It was a good winter break. I took off some time from work to spend with my family, my parents flew in, we hosted a New Year’s Party for a large group of fri...

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2017

2017 AMC 8 Questions

2 minute read

We finally received our scores. Overall I always have to remind myself that “comparison is the death of joy”.  But really I think the kids did very well and ...

12/12 End of Quarter

2 minute read

The end of this quarter really snuck up on me.  In my planning process I decided to finally use the video below on  Schumann’s enumerative Geometry. What I p...

12/5 Olympiad #1

1 minute read

Today was the very delayed first MOEMS middle school contest day.  As I mentioned before this contest was supposed to be on the same day as AMC 8 so we had t...

11/7 Decoding

3 minute read

I decided to do a second smaller sampler of AMC 8 problems for Math Club this week.  Unlike last week (see: 1031-put-a-bird-on-it)  this time I wanted to app...

10/31 Put a bird on it.

2 minute read

Its the math worksheet version of “Just put a bird on it.” https://t.co/lNP3fs0wA2 — Benjamin Leis (@benjamin_leis) October 31, 2017

10/25 Strange Bases

3 minute read

This was a funny week. All the eighth graders were out on the class trip so Math Club skewed younger. That played a part in my planning. I aimed a bit less c...

This year’s Math Count Poster

less than 1 minute read

The poster arrived in the mail with the rest of the contest materials. I think its charming and hopefully I can get permission to post somewhere in the school.

Heron’s Formula

3 minute read

The MathCounts guide for the year arrived today and I was looking over the problems. The following one caught my eye.

10/17 Pythagorean Triples

2 minute read

12-triangles-and-their-link-to-pythagorean-triples The inspiration for this week was a puzzle from the recent Pythagorize Seattle event thrown by MoMath that...

10/10 Middle School

less than 1 minute read

In a careless move I deleted my original post on this one. Here’s a skeleton version until I have time to rewrite it.

Teasers for this year

1 minute read

Things are moving along. I have a provisional process to get going in 3 weeks and I’ve sent out the initial signup forms.

How I use Twitter

3 minute read

This post started with some musing about the meta conversations occurring online right now in twitter over hashtags.  There was enough activity that I was di...

Angle bisector

4 minute read

I’ve officially reached the point of the Summer where I’m missing interacting with kids besides my own.  In the meantime, this is another geometry walk-throu...

Differentiation Part II

2 minute read

Continuing on my thinking from last time:  open-ended-problems I saw notes on an interesting recent talk from @cheesemonkeysf

Open Ended Problems

3 minute read

I’ve been thinking more about open ended problems after reading a couple of different posts recently. Full disclosure: I actually engage in problem solving e...

Double angles

2 minute read

I’ve been thinking about a generalization of the 15-75-90 construction over the last few days and have realized there are a lot more interesting consequences...

And yet more 15-75-90 fun

1 minute read

Continuing on the theme of 15-75-90 triangles (See: Last time and First Time) several interesting riffs on 15-75-90’s in a box have come up recently.

Factoring Proof

2 minute read

One of the fun possibilities next year is that we can do problems with polynomials and factoring (at least by the end of the year.) I was reading a post by @...

Ideas for Next Year

less than 1 minute read

It was a good week for finding inspiration on the internet (and in some books from the library). This is a grab bag of ideas for next year based on what I ha...

2017 Year in Review

5 minute read

One of the big questions I had going into this year was “Will the Math Club be very different this year? Am I going to continue…

6/13 And its a wrap

1 minute read

I was really heartened after sending an email out last week that all of the kids made it to Math Club today despite the…

6/6 Rational Tangles

4 minute read

This Math Club  was a growth exercise for me. I had decided a few week’s ago that I wanted to do John Conway’s rational tangle game: http://www.geometer.org/...

15 - 75 Triangle Redux

less than 1 minute read

I came up with this problem after looking at the original one from @five_triangles (Find the area of the trapezoid ABCD) That’s a lot of fun but along the way…

5/23 Triangle Conundrum

2 minute read

In the middle of last week, the MOEMS awards for the year arrived. So I started handing out patches and medals. I’m fairly happy with our overall performance...

5/16 Expected Values

4 minute read

My planning process this week went something like this: after last week’s talk I either wanted to do some group white-boarding or find a new game to explore....

MathCounts Final

1 minute read

Since it was fun Last Year to think about the Math Counts final question, here is the 2017 version:

Questions for Mathematicians

7 minute read

I’ve been prepping for our guest talk from the UW Math Dept. One of the tasks I’ve done is survey the kids to generate questions for the talk. Jayadev Athrey...

5/2 Assessment

1 minute read

This is a short placeholder entry.  I decided to administer the AoPS algebra assessment last week since the 5th graders are currently choosing next year’s ma...

4/25 Platonic Solids

5 minute read

This week’s inspiration started with a very late school bus. My son’s bus driver has been on vacation and the substitute drivers have been really, really tar...

Spring Break Geometry

3 minute read

[In exciting real news, I almost have a guest speaker from the UW Math department lined up for May. My hope is that this will be helpful in showing the kids ...

4/4 Spring Quarter Begins

4 minute read

This quarter began with a seamless transition the week after the old one ended  However, I had a little bit of turnover with 2 kids leaving and 2 new boys an...

3/28 #VNPS

3 minute read

Today was a fascinating learning experiment for me. I recently watched the following lecture:

3/21 Graph Pebbling

1 minute read

This week I went back to a pure math circle format with my favorite activity from the recent Julia Robinson Festival: Graph Pebbling. Based on my experiences...

3/14 Pi Day

1 minute read

Every 7 years or so accounting for leap years, Pi day actually occurs on a Tuesday. Yesterday was the first time that occurred…

3/7 Olympiad #5

1 minute read

Today started with a small mix-up. A boy I recruited at the Julia Robinson Festival to join Math Club showed up. But the next quarter doesn’t start for 3 wee...

2/28 Infinite Series

2 minute read

For this session of Math Club I wanted to revisit one of the ideas from the “free the clones” games: (See: 131-chessboard-problems-or-manipulatives-on-the-ch...

Julia Robinson Festival

1 minute read

(The flatland talk at the end of the afternoon.) For the second year in a row, I volunteered at the Julia Robinson Math Festival over the weekend. This is…

My own Geometry Puzzle

less than 1 minute read

(This is based on my previous explorations of the @solvemymaths problems. As far as I know its a new so I’m very happy with it. Usually I just collate probl...

Making Explorations Successful

2 minute read

In a fit of perhaps excessive caution, the district cancelled all after school activities today despite the snow being almost completely melted.  So I’m tabl...

1/24 Curve Ball

5 minute read

Sometimes random events complicate the best of planning. I was on my way to work when I received an email from my co-coach Kristie that  her plane was delaye...

1/17 3rd Olympiad

5 minute read

We started this week with the pdf from further maths that I gave out as a problem of the week: http://furthermaths.org.uk/docs/FMSP%20Problem%20Poster%201.pd...

1/10 New Year’s Celebration

4 minute read

Its gratifying when you plan a Math Club session where your time estimates work out and you achieve really good engagement.  I had a few goals for this time ...

Knight’s of Pi 2017

3 minute read

High School full of mathy kids assembling for a Math competition. This weekend was my third time back at the Knight’s of Pi math competition and I brought 2…

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2016

Technology

2 minute read

I saw a funny ignite talk “Algebra Inferno” the other day comparing disliked teaching practices to the various circles of hell a la Dante.

Winter break cyclic 3-4-5

2 minute read

This is another exercise in documenting geometry problem solving. I chose this problem because again it has a 3-4-5 triangle within it and the overall setup ...

2016 AMC 8 Results

1 minute read

The wait is finally over. We received the results for the 2016 AMC 8.  Now comes my least favorite part sending them out to the parents.  This is the message...

12/13 End of the Quarter

4 minute read

And just like that, another quarter has wound down.  I’m always amazed how fast time flies. Its a lot of work planning and running the sessions of Math Club ...

12/6 Catching Up

3 minute read

As I alluded to in my last post I had to miss last week’s Math club meeting. This was one of those times when expanding to two instructors really paid off. T...

Grab bag of problems

1 minute read

Sadly, I  have to miss Math club on Tue. given a family emergency. In the meantime, these are some of the problems I’ve enjoyed looking at recently that I mi...

11/15 AMC8 and some Topology

3 minute read

What a difference a week makes. I left yesterday feeling very upbeat. To start off, I drove to the school early to help escort nine of the kids over to our s...

11/8 Election

1 minute read

This was a pretty raucous session. I didn’t really anticipate how much the kids in the Math club would be invested in the election. I was peppered with reque...

11/1 Grid Puzzles Again

less than 1 minute read

This is a short placeholder for my records. The synopsis for this week is I did the following logic grid puzzle:

10/25 Gozen

2 minute read

It was an interesting week from a planning perspective.  I’m  almost finished emphasizing divisibility and trying to decide what area I’d like to turn to nex...

10/18 More divisibility

4 minute read

After a slow start last week, this time almost all of the kids in the Math Club finished the problem of the week.  (See the end of this post)  I had one of t...

10/3: Year 3 (Bigger and Better)

4 minute read

I always get an odd mixture of impatience and trepidation right before after school activities start up. This time most of my concern is around getting two r...

Continued Fractions Planning

less than 1 minute read

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Prime Number Planning

less than 1 minute read

I’ve been thinking about what a prime-number themed day would look like based on some questions on Facebook. I’ve done prime related topics here and there bu...

2016 Year in Review

5 minute read

With another year under my belt, its time to look back and think about what I’ve learned over the process.  (Here’s my review from last year: the-year-in-rev...

Two problems I’m looking at

2 minute read

I was reading a fun post over @ http://eatplaymath.blogspot.com/2016/06/my-first-problem-set-for-my-problem.html where Lisa is brainstorming problem sets. Sh...

6/14 End of the Year

1 minute read

And so we reached the end of another year.  I wanted to celebrate a bit for the last day so I ordered a supermarket cake and we had a small party in the…

6/1 Art Math Intersection

2 minute read

I farmed out picking candy for math club to my wife this week and she was very generous in her purchases.  So I started the day handing out skittles and gumm...

5/17 Battleship

2 minute read

The kids surprised me twice today during Math Club. We started by going over the Math Counts problem of the week I tried out: https://www.mathcounts.org/site...

2 Fun 3-4-5 Pythagorean Triples

1 minute read

I’m going to warehouse these problems from @five_triangles here. I really like how they both show constructions for a 3-4-5  Pythagorean Triple. My plan is t...

5/10 Connect the Dots

3 minute read

Around the middle of last week I received a surprise phone call from the school office: “Your package arrived and we’re holding it for you.”  As expected, it...

5/3 Square Roots

2 minute read

This week’s theme was inspired by some of  questions the kids had while working on the Pythagorean Theorem about finding square roots. I have a small collect...

You don’t always win

1 minute read

“I want to thank everyone for coming out over spring break. I hope your kids had fun.  I really enjoyed seeing everyone competing and talking with all the ot...

4/5 Snap Cube Hotel

2 minute read

Before this week’s Math Club meeting I had an extra math adventure. This weekend was the Julia Robinson Festival at the UW (http://jrmf.org/). I drove to the...

3/22 Winter Game Day

1 minute read

I had to hold back a laugh this week. While waiting for everyone to arrive in the cafeteria, one of the kids asked if we were going to have pie again. “If yo...

3/15 Pi Day 2016 (more or less)

3 minute read

One of these years Pi Day will actually occur on the day Math Club meets. Until that happens it also serves as a demonstration of  approximation for the kids...

3/8 Olympiad #5

2 minute read

We finally reached the last Math Olympiad for the year. Earlier in the week I had received a mail from MOEMS giving some corrections for the third problem. S...

3/1 Fold and Cut

2 minute read

Even after two years, I’m still experimenting and searching for new material. Case in point, yesterday was notable for two changes.  I had decided after last...

2/23 Prepping for Pi Day

4 minute read

Riff on the what I want the group to focus on I was reading a post on the natural math site: http://naturalmath.com/math-circles-1001-leaders-course/  around...

President’s Day Break Geometry

4 minute read

There’s no school on Tuesday for President’s day and therefore no Math Club. If I had realized this more fully I would have perhaps picked an extra problem o...

2/9 Olympiad #4

2 minute read

This week started with the kids getting agonizingly close (19/20 problem of the week points) to a reward. I’m hoping this tension plus the fact I printed thi...

2/2 Space Math

2 minute read

This week started with lower problem of the week participation than in the past probably due to the fact I didn’t provide a handout and just orally gave the ...

Extra Reading

3 minute read

There’s been a spate of an interesting articles popping up on the web recently. The first one was from David Wees: http://davidwees.com/content/planning-less...

1/26 Recycler

3 minute read

It was another good week for participation. I had 8 responses to the problem of the week and almost everyone found the answer. Interestingly, this is officia...

1/19 Third Olympiad

3 minute read

There was lots of good stuff this week. First off, I had 9 kids work on the problem of the week including several of those who just joined. That meant I coul...

1/12 Human Calculators

3 minute read

This week Math Club started up again although sadly without my son who had a fever and stayed home.  There are seven new kids to get to know and I’m on a goo...

Preparing for the new Quarter

2 minute read

Next Tuesday will be the first session of Math club for this quarter. As a result, I’m in the last stages of planning this week. One monkey wrench for me is ...

An Update on DreamBox

2 minute read

I’ve now watched about a month more of my son’s play with DreamBox. So this constitutes an update to my prev. post: a-review-of-dreambox

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2015

12/15 Olympiad #2

3 minute read

Once they get started, the MOEMS Olympiads come quite frequently. This month’s version surprised me because in my first glance I had thought we had only had ...

Knights of Pi 2015

3 minute read

Last Saturday I once again found myself at Newport High School in Bellevue for the Knights of Pi Math Competition. This year I brought one team mostly of fou...

12.8 (Math) Game Day

1 minute read

This will be a shorter post than usual since I left my camera at home, I have a math contest to talk about after Saturday and today was all about play.

Blog Anniversary.

2 minute read

Why Blog? Its been about a year, 75 posts and 3900 hits since I first started blogging.  So it seems appropriate to step back and ask some bigger questions. ...

12/1 The power of 37

3 minute read

This week I led math club by myself. I decided I would focus on a pair and share exercise where we’d work through 3 problems and spend time explaining answer...

A review of dreambox

2 minute read

This week is Thanksgiving break and there are no Math Club meetings. Instead I thought I’d write down my thoughts about dreambox.com, an online math app. I’v...

11/17 First Olympiad

3 minute read

Today was a really fun day in the math club. We started with me handing out whoppers to everyone as they arrived since the kids had reached our next goal for...

11/10 Relay Madness!

2 minute read

After my bad activity complexity estimation last week it was a relief to properly size the planned exercises for math club this time around.  We started by g...

11/3 Oops I did it again

2 minute read

This week I did a great job planning to ensure continuity, rolled with how things played out in the room and didn’t finish nearly as much as I wanted to. sig...

10/27 First Practice Olympiad

3 minute read

The most exciting part of this week was I think I’ve found another father who is willing to help assist me. Today was his first time coming and helping out. ...

10/20 Grids and Graphs

2 minute read

This week I planned a series of more playful activities. We started with a review of the take home problem of the week: (September from www.moems.org/zinger....

10/6 And we’re off to the races

2 minute read

This afternoon was finally the first meeting of the math club for the year! Things started with a rude shock when I checked out my assigned room and found it...

Reversing digits

3 minute read

Moderator Note:  What’s better than one semi math-crazy after school coach? How about two of them. My friend Dan has agreed to run our feeder Middle School’s...

Demographics

less than 1 minute read

I just received the roster list. So some quick demographics for the beginning of the year.

8/17/15 Pythagorize Seattle Photos

less than 1 minute read

Today MoMath celebrated the Pythagorean Triple comprised of  the date: **8^2 + 15^2 = 17^2 **with a math happening at South Lake Union. In case its not obvio...

The Geometric Mean

less than 1 minute read

I’ve been thinking a bit about the geometric mean this week after it turned up in two separate 

Summer Reading

less than 1 minute read

This book just arrived in the mail yesterday. I tried the first few problems out last night to escape the heat and they were pretty fun.  They also despite t...

How to make homework work

1 minute read

Just yesterday AoPS released a new online problem resource for Middle School level (MathCounts) material: http://artofproblemsolving.com/mathcounts_trainer. ...

Random Geometry Recursion

less than 1 minute read

You can recursively keep halving the length of the diagonals in this fashion. Creating a series of smaller 30-60-90 triangles in the process.  (I promise I ...

Geometric Translations

1 minute read

Recently inspired by some posts on problem solving over at problemproblems.wordpress.com I’ve been combing through the geometry problems at gogeometry.blogsp...

The Year In Review

4 minute read

Now that the last session of the math club is done for the year it seems appropriate to look back and reflect on my experiences. Going into the process, I th...

6/9 End of the Year

1 minute read

Today was the last meeting of the math club for the school year. I feel a bit elated to have made it through an entire year and sad at the same time to see…

On Hints

3 minute read

I’ve been reading the following thought provoking post by Michael Pershan @

5/26 Gamification

1 minute read

Today I tried something completely different with the math club. We participated in the Washington State Algebra Story Problem Challenge. http://wa.algebrach...

Virtual Math Club

less than 1 minute read

Tomorrow our district is shutting down while the teachers go on a one day walk out. As a result there will be no math club session.  But that’s no problem - ...

5/12 Dog + God

2 minute read

I have a lot of interesting observations from math club today. First up, for the warm up I went with some decoding problems:

4/21 Purple Comet Online Meet

6 minute read

This week of math club we tried out the online Purple Comet Math Contest. http://purplecomet.org. Running the contest required a few modifications to our nor...

Simplifying a Proof

1 minute read

I found this problem online yesterday (briefly) via a post on the google+ k-12 education.  In the figure below

4/7 Spring Quarter Starts

2 minute read

Today was the first day of our last quarter for the math club. I lost 2 kids from the winter session that were replaced with 3 new ones. (I’m embarrassed to ...

Math is Cool 5th Grade Contest

2 minute read

This was my second contest experience. I brought 2 teams of four this time and because of a late withdrawal ended up drafting my son to fill the last spot. S...

3/10 Pi Day (approximately)

3 minute read

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3/3 Olympiad #5

2 minute read

After many of the kids asking about them, I finally brought some Sudoku puzzles to warm up on this week. I learned my lesson from ken-ken and only printed an...

2/24 Combinatorics

3 minute read

This session I decided to try out some more of the fivetriangle problems. I gave out a double sided sheet with 2 problems on it and let the kids decided whet...

Triangle Number Exercise

1 minute read

Admin note: This is my first experiment getting latex formatting working for formulas so there’s going to be more sigma notation than I would use in class. W...

2/10 Olympiad #4

2 minute read

Olympiad days usually go well and this one was no different. (Perhaps this means I should introduce more competitive tasks on regular days despite my instinc...

2/3 Finish what we started

1 minute read

My main goal for this week was to get to all the problems we didn’t do last week after our KenKen digression.  So I started reviewing the AMC8 6-10 problems....

1/27 KenKen Collaboration

1 minute read

As originally planned I wanted to work more on collaborating together today. So I had everyone give me their names on a slip of paper and I then  paired ever...

Can we get from here to there?

1 minute read

I’ve been looking at the five triangles site recently: fivetriangles.blogspot.com and I like alot of the problems there. I’m now considering whether the most...

1/20 Math Olympiad #3

2 minute read

So this week was our third MOEMS Math Olympiad. I brought cupcakes again since they struck such a deep chord with the kids the first time. In the interest of...

Rescuing a poorly designed worksheet

less than 1 minute read

So my son brought home a math worksheet/game to do over the winter break. It involved rolling four six-sided dice and adding them into 2 sums and then multip...

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2014

Puzzle for the break

less than 1 minute read

I love breaking substitution ciphers. I sent one out before the first meeting in the fall and I decided I would do another one before our second quarter.

Odds and Ends

1 minute read

So officially we’re on winter break and the club will not meet up again until January. It’s also reregistration time. This had led me to imagine a few scenar...

Knights of Pi Math Competition

3 minute read

Finally, our first off site competition! Nevermind that it was scheduled for the first Saturday of the winter break so most kids couldn’t come, I was really ...

12/17 Math Olympiad 2

2 minute read

So MOEMS released the January test last week and I realized that given our school schedule it would  be best to run the contest this week rather than scrambl...

Classroom Management

1 minute read

Going into the process, I worried most about handling a large group of kids at once.  I’ve never done anything exactly like this before and my closest experi...

12/9 Prime Climb

2 minute read

I’ve already tried a few different games out and they’ve always worked really well especially for drawing out kids who don’t raise their hands as often. Howe...

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