The exercise collection
Pick one, grab a scrap of paper, and see if your gut agrees with the arithmetic.
Fold it to the Moon
How many times must you fold the sheet so that its thickness reaches the Moon?
Try it →
How much does the world poop?
How much poop does humanity produce per second?
Try it →
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 →
How many heartbeats in a life?
Roughly how many times will it beat over an 80-year life?
Try it →
Pizza for a sold-out stadium
How many giant (35 cm) pizzas do you need to order — and do they even fit on the pitch?
Try it →
Shower the lake
If you drained the lake one 10-minute shower at a time, how many showers would it give?
Try it →
Walk around the Earth in one lifetime
Over 80 years, how many times around the Earth would your feet take you — and how many pairs of shoes would that wear out?
Try it →
How long is the Italian debt?
How long would that line of coins be?
Try it →
A crowd the size of Rome
If everyone on Earth stood shoulder to shoulder, how much land would we occupy?
Try it →
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 →