​What are Pairs?

Pairs are groups of two. Whether or not you have a complete set of pairs will determine if the number is odd or even.

​Counting by 2s into Pairs

• To the right are 6 circles.

• The six circles are divided into pairs of two's using the lines.

• There are 3 COMPLETE pairs, meaning that the number 6 is even.

​Example of Using Pairs

• To the right are 5 circles.

• These circles are also separated into pairs using the lines.

• There is one incomplete pair, meaning there is only 1 circle instead of 2

• This means the number 5 is odd

​What Does it Mean When a Pair is Not Complete

Counting by 2s

​Counting by 2's helps determine pairs.

• If you can count by 2's to reach a number, that means the number is even.

• For example, if you are asked if the number 8 is even, you can count 2 - 4 - 6 - 8. Since you can count to 8 by 2s, that means it is an even number.

• Another example is if you were asked if the number 5 is even. You can count 2 - 4 - 6. Counting by 2s skips the number 5 meaning it is not even, but odd.