Near-Doubles Addition

Near-Doubles Addition

A near-double is an addition fact where the two numbers are almost the same, differing by 1. This strategy helps you use a fact you already know to find the answer faster.

1) Find the double

Look for the smaller number and think of its double.

• Example: for 6 + 7, the double of 6 is 6 + 6 = 12.

2) Adjust by 1

Since the other addend is 1 more, add 1 to the double.

• 6 + 7 = 12 + 1 = 13

3) Work with either number

You can also start with the larger number’s double and subtract 1.

• For 8 + 9, double 9 is 18, so 8 + 9 is 18 - 1 = 17.

4) Check your answer

Make sure the result is one more than the double of the smaller number, or one less than the double of the larger number.

Quick examples

• 4 + 5 = 4 + 4 + 1 = 9
• 10 + 11 = 10 + 10 + 1 = 21

This method is especially useful when the numbers differ by 1 and you want to build speed and confidence with addition facts.