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!

UPDATE – check out the beta version of our new Broken Calculator warmup website here.

This is a good early Broken Calculator to use.

More advanced versions might remove the “+” sign.

Even more difficult: remove the “+” and “-“.

With a blank board, you can make your own broken calculators.
You can even print out the image and cover the “broken” buttons with post-it notes.

Check out:

Broken Calculators from the Julia Robinson Math Festival
New York Times Numberplay Broken Calculator Problem

You can also find another take on Broken Calculators in our lesson writeup here.