Math = Love: Make It Even Brain Teaser

Tuesday, September 29, 2015

Make It Even Brain Teaser

Last Friday, I pulled a new-to-me brain teaser out for Figure It Out! Friday.

I found a puzzle called "Make It Even" in The Moscow Puzzles: 359 Mathematical Recreations by Boris A. Kordemsky.

The book is published by Dover, so it's super affordable at $3.99!  I've found numerous puzzles I want to try out with my students.  This is the second week in a row that our figure it out puzzle has come from this book!

The original puzzle called for 16 objects.  I decided to use bingo chips since I have a giant bag.

To save time and not have to bag up 16 bingo chips per student, I took a package of 5 plastic bowls I bought at Dollar Tree for $1 and divided the bingo chips into these bowls.  The bowls are cheap feeling, but at $0.20/piece they are amazing!

Here they are, stacked and ready to go.

My Algebra 2 students and Stats students were much better at reading the instructions and attempting the puzzle on their own.

My Algebra 1 students struggled even when I read the instructions to them.

There were a ton of "This is too hard" or "This is impossible" comments.  In each class, at least one student figured it out though!

I can't tell you how many times a student would raise their hand to have me check their solution, and I would walk over to find that they had a column or row with one in it.  I think they were just too focused on making the rows even or making the columns even to even look at it the other way.

Part of me now wonders if students would perform differently on this task if it was presented differently.  Maybe like this?

Some of my students tried rearranging the 10 leftover chips into 2 rows of 5.  I think this second phrasing of the problem would prevent that.  If I did the second version, I'd definitely give it to my kids inside a dry erase sleeve.

Or, maybe combine the two methods and give students the grid and only 10 chips?


  1. This looks like a great resource!

  2. I was just thinking to myself...what should I do for the Friday warmup? And I have that book :) I kind of like the idea of giving some groups chips & other groups the board in dry erase sleeves and then discussing which strategy was more effective or which one they liked more.

    1. If you try it, you'll have to let us know how it goes!

  3. Hey Sarah: I tried this activity with my Grade 6 math students who are withdrawn for math from their regular program as an introduction to arrays. First of all, they loved it. And second of all, they were thrilled when they figured it out! It required some grit and perseverance, but the smiles on their faces when they were successful was the highlight of my year so far. Thanks for sharing.

  4. I can't figure it out! Can you stack the chips?

    1. Nope. No stacking :) I promise it's possible.

  5. Just to clarify. Is it even as in the same.. or even as in not odd?

  6. Starting with the first column, remove the 2nd and 4th chips. In the second column, remove the 1st and 4th chips. Finally, in the last column, remove the 1st and 2nd chips. =)