Broken Calculator Warm Up

Broken Calculators are one of the most versatile and delightful openers I know. The image itself communicates the heart of the puzzle, while leaving students open to all manner of different and personal approaches to reaching the goal. Read the lesson below, and check out the images underneath. It’s easy to make your own! This is a good early Broken …


2, 4, 6 Puzzle

The 2-4-6 Puzzle teaches an invaluable lesson about inductive reasoning, confirmation bias, and how “wrong” answers lead to deeper knowledge. It can be adapted with different rules for endless play options and difficulties. Also see Josh Golden’s writeup of Eleusis Express for a card game version of the game, perfect to play with standard cards, SET cards, or Tiny Polka …

Subtracting Reverses

This extraordinary lesson combines base ten subtraction practice with an irresistible mystery. A pattern slowly reveals itself as the class compiles data.

Billiard Ball Problem

The Billiard Ball Problem is a beautiful exploration of a situation both natural and novel. Great for problem solving, with connections to ratio and proportion. Also check out this Billiard Ball simulator on Scratch.

Penny, Nickel, Dime

This version of Don’t Break the Bank is a hit with students, and also helps give a concrete meaning to place value by linking it to both money, addition, estimation, and multiplying by fives and tens. It takes very little time, so it can be used as a warmup, station activity, or in those five minutes before class ends. While …

Math Magic Trick

This trick is an extraordinary introduction to the power of algebraic thinking, and a reminder of what makes algebra so awe-inspiring. A video Launch for this lesson is available in two parts. PDF of the lesson is below the videos. Part 1. When using as a class launch, stop at 2:45 and let the class come up try to find …


Story Problem – The Monster

For this long-form story problem, read the story to your class first, then give them the questions to answer, and the story as a reference. Optional artistic tie-in: draw a picture of the monster. Optional challenge: write another question about the story.

Pyramid Puzzles

Pyramid puzzles are a fun and deceptively tricky puzzle. Sometimes these can’t be done without some risk taking—encourage guessing and checking, and learning from the inevitable mistakes, especially on the harder puzzles. More on Pyramid Puzzles here.