Digits and numbers

When we read 17 we say "seventeen". But what are these little signs we write — the 1 and the 7? Those are called digits.

What is a digit

A digit is one symbol. There are exactly ten of them in the whole world:

0, 1, 2, 3, 4, 5, 6, 7, 8, 9

That is it. Just ten. Every number you will ever meet — even the biggest ones — is built only from these ten signs.

What is a number

A number tells us how many. Some numbers are written with one digit, some with two:

• 7 is a number written with one digit.
• 14 is a number written with two digits — first 1, then 4.

A small game

Look at the number 18. How many digits does it have? Two. Which digits? The digit 1 and the digit 8. And what is the whole thing called? The number eighteen.

Now you try with 12, 5, 20.

Why this matters

When we say "write the digit", we mean draw one symbol. When we say "write the number", we may need one or two of them. Knowing the difference helps you read big numbers later.

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