Kaitlyn was asked to solve for the unknown. The problem
shows that n +.6 = 13. Her steps are shown below.
■ She started with 6 tiles.
Then she added tiles as she counted up to 13.
Kaitlyn realized that she added 7 more tiles to her
original 6 in order to make 13.
The unknown number is 7.
Intro
How could Kaitlyn check her work? Check all that
apply.
k
She could substitute 7 for n and add.
She could subtract 6 from 13 and check that the
answer is 7.
She could subtract 7 from 13 and check that the
answer is 7.
She could substitute 6 for n and add.
She could put all the tiles in 1 pile and count them
to see if there are 13.
Done