Everyday numbers, silly questions, real math.
A collection of invented mental exercises taken straight from daily life — folded paper, toilet paper, pizza, showers. No classroom tone: just numbers you can almost hold in your hand.
✨ Newest exercise
NEW7 min
A lifetime at the keys
How many times does a professional pianist press piano keys in a lifetime? And how many times the white ones versus the black ones?
Try it →Exercises
10 min
Fold it to the Moon
How many times must you fold the sheet so that its thickness reaches the Moon?
Try it →
7 min
How much does the world poop?
How much poop does humanity produce per second?
Try it →
8 min
The great toilet-paper odometer
How many rolls of toilet paper does the whole town use in a year — and if you unrolled them into one strip, how far would it reach?
Try it →Coming soon: the numbers buddy
We are working on an assistant that will nudge you through the exercises and check your calculations — no spoiling the answers, promise.