Class 9 Mathematics

NUMBER SYSTEMS

Natural Numbers

The numbers we commonly use for counting are called Natural Numbers.

1, 2, 3, 4, 5, ...

The dots ... mean that the numbers continue forever.

1 book

2 books

3 books

4 books

KEY IDEA

Natural Numbers are used for counting.

There is no largest Natural Number.

No matter how large a Natural Number is, we can always add 1 to get another one.

1000 + 1 = 1001

BUT WAIT...

Natural Numbers help us count things.

But what if we have nothing?