We’ve argued for a long time that the real experience of mathematics is inextricably tied to play. But if you’re a parent or teacher, you’ve seen kids play in mathematically irrelevant ways. How do we hit that sweet spot of mathematical play? One way is to recognize mathematical questions and ideas when they arise from the play itself. Another is …

## what’s awesome about algebra

As students are enrolling in pre-algebra and algebra in droves, I thought I would post this video, which is part 1 of a magic trick illustrating the mind-boggling power of algebra. It is very common to learn how to do algebra without learning why to do it. To me, this magic trick gives a sense of how useful and powerful …

## Primo – the beautiful, colorful, mathematical board game

Primo A Totally Unique Mathematical Board Game from Math for Love More than a year ago we had an idea to build a game around what felt like one of the unsung ideas in math: prime numbers make multiplication easy. (Why does no one learn this in school?) We realized that with the right color-coding, it would be possible to …

## Announcements

Note: The Math for Love newsletter does not usually get posted on the blog. If you’d like to sign up, enter your name and email in the sidebar. Here are the announcements from our last one. A Coin Problem I’ve posted one of my favorite problems of all time as this week’s NYTimes Numberplay puzzle. Consider this simple game: flip …

## 1-2 Nim Write Up

I’ve been taking some time to write up some lessons, and I’d love to get some feedback. You can click here for a pdf of this lesson on 1-2 Nim. It’s one of our favorites: a surefire way to get students of any age playing and thinking. The question is: how’s the write up? We’ve been shooting for 1-2 pages maximum, so …

## A spoonful of transgression

I was just observing a third grade class learning/reviewing basic fraction to decimal conversion, and I overheard a great remark. A girl, reading a word problem, said to her table mate, “Jessica ate 6/10 of a cake?! She’s fat.” There’s a part of me that hates comments like that, and a part that loves them. I hate the comment because, …

## Productively Stuck

When I try to describe great teaching, I notice a certain phrase pops out of my mouth again and again. Productively stuck. As in, the goal of the teacher is to get her students productively stuck as soon as possible. As in, we want to hook the students with a compelling question and then leave them productively stuck. As in, …

## Can Modesty Cure a Hurry?

ANNOUNCEMENT: Sign up now for our Common Core Crash Course for 1st-5th grade teachers, this August 20-21 in Seattle. __________________ It’s happened to every teacher. It’s Thursday, but your students don’t seem to remember Wednesday or Tuesday, and you’ve got three times as much material to cover if there’s any chance of Friday’s lesson working. Finally, you gather them together. …

## Proofiness

When Stephen Colbert introduced the word truthiness on his show, he told us to trust our guts. That’s where the truth comes from, ladies and gentlemen: in the gut. Do you know that you have more nerve endings in your stomach than in your head? Look it up. Now somebody’s going to say, I did look that up, and it’s …

## A curious inversion problem

I’ve been exploring a new problem with a couple of students recently that I find incredibly compelling, and I thought I’d mention it here. The main idea is looking at the behavior of functions of the form f(x) = ax + b in various mods. There’s actually a huge amount to explore here, from fixed points to invertibility to the …