Question

Mrs. Dinson has 9 pencils on her desk. She has 3 pencils in a box. To find the number of pencils she has altogether, Mrs. Dinson writes 9 +3 = 12. What other addition fact could Mrs. Dinson use?

Answer 1

The sum of two equal addends will always yield the same result.

1) Considering that Mrs. Dinson has 9 pencils on her desk and 3 in a box, we can use the following addition fact:

The sum of two equal addends will always yield the same result.

That's why 9 +3 will always yield 12 as well as 3 + 9 =12