🔢 Numbers

The Romans had no symbol for zero. A 'googol' is a 1 followed by one hundred zeros. A “googol” is the number 1 followed by 100 zeros. Numbers help us tell how many things there are. Zero is the only number that can't be written with Roman numerals. Counting numbers go on forever — you can always add one more. If you could fold a piece of paper 42 times, it would reach all the way to the Moon. We write every number using just ten digits, 0 through 9. The word 'four' is spelled with four letters — the only number in English like that. Zero is the number that means 'none'. In a room of just 23 people, it's more likely than not that two share a birthday. The number after 9 is 10, our first two-digit number. Any number multiplied by zero is always zero. A 'million' is a 1 followed by six zeros. A 'dozen' means 12, and a 'baker's dozen' means 13. The number shapes we use, like 1, 2, 3, first came from India. A 'googolplex' is an even bigger number — a 1 followed by a googol of zeros.