All whole numbers are either **odd** or **even**.

Odd and even numbers run one after the other as we count.

Counting to 20 below the odd numbers are in green, the even ones are in blue:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20

There are two ways to check if a number is odd or even.

Method 1

Look to see what the **last digit** of the number is.

All **even** numbers end in **2, 4, 6, 8 or 0**.

All **odd** numbers end in **1, 3, 5, 7 or 9**.

Method 2

**Divide** the number by **2**.

**Even numbers** like 2, 4, 6, 8, 10, 12… all **divide exactly by 2**, they can be halved to form another whole number.

**Odd numbers**, such as 1, 3, 5, 7, 9, 11, 15, 17… **are not divisible by 2**, they will not split in half to form another whole number, they leave a half number such as 12.5.

Example

**Question**: Is 58 an odd or even number?

58 ends in **8** which tells us it is **even**.

Also 58 can be **divided by 2**, which tells us it is even:

58 ÷ 2 = 29

Question: Is 29 an odd or even number?

29 ends in **9** which tells us it is **odd**.

Also, 29 **does not divide by 2** to form another **whole number**, which tells us it is odd:

29 ÷ 2 = 14.5

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