Zero is the number that comes before one, the number that stands for “nothing”. For example, if I had three books and gave you two, then I would have one book left. But if I gave you all three books, then I would have none left – that is, I would have zero books left.
It might seem strange to have a number for nothing. That might be why it took so long to be invented. But zero makes arithmetic far easier. For example, before zero came to the West, multiplying numbers was something only experts in the field could do. But with zero even an eight year old can do it.
Today in the West we write the numbers from one to nine this way: 1, 2, 3, 4, 5, 6, 7, 8 and 9. Zero is written this way: 0. Those are all the numbers we need.
But how, then, do you write ten or twelve or fifty-two or six hundred? Like this: 10 (ten), 12 (twelve), 52 (fify-two), 600 (six hundred).
Six hundred and fifty-two looks like this: 652. What does that mean? It means:
six (6) hundreds and
five (5) tens and
The position of a number matters:
six hundred: 600
six thousand: 6000
six thousand and fifty-two: 6052
And that is the power of zero: it holds a place where there is nothing. 600 means six hundred and zero (0) tens and zero (0). Which might seem to be a strange way to think of it, but it makes the number much easier to handle.
We think of inventions as building on what came before and becoming more and more difficult to understand and make. Most are like that. But every now and then a true genius comes along and invents something that takes a hard thing – like arithmetic or reading – and makes it easier. The codex, the fork and letters are all examples of this.
Before zero people thought that multiplying numbers had to be hard – there was no way around it. Not so!
Zero was invented at least two times: first by the Olmecs in Mexico by 36 BC and again 400 to 500 years later in India. The Babylonians had something close to zero but it did not take hold – unless, of course, that is where India got it from.
The Greeks had a sign for zero but it was just something added to their number system. For all their genius they never got farther than that. No one knows why, but it is probably because they thought in geometry not in numbers. Geometry and number were not united into one solid system till the 1600s by Descartes.
The West got the zero and the new number system from the Arabs. We know because the word “zero” comes from Arabic. It came in the 1100s but it took centuries to really take hold. Even today you still see the old Roman numbers here and there.