Natural numbers are positive numbers from 1 to infinity. They do not include the number zero or any negative numbers, fractions or parts of numbers.

They are sometimes called counting numbers:

1, 2, 3, 4, 5, 6  are all natural numbers, as are 27, 435 1,000,000 etc.

Whole numbers are counting numbers but also include zero:

0, 1, 2, 3, 4, 5  etc.

Integers are positive and negative whole numbers and zero:

..... -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5 .......

These are not difficult to understand but they can be hard to remember!! 

The best way to learn this is to practise - let's get started now!