Write a doubles fact you can use to find the sum of 6+7

We could use 7+7=14 to find the sum of 6+7.

Explanation:

7+7=14 is one of the two closest doubles to 6+7.

We know that:

7 is 1 more than 6; this means:

7+7 will be 1 more than 6+7.

7+7=14, so finding 1 less,

6+7=13.