Question

Use a model or paper and pencil to add. Write your answer in simplest form.

9/12 + 6/12

Answer 1

9/12 + 6/12 = 15/12 = 1 3/12 = 1 1/4

Answer 2

We know that 9 cows + 6 cows add up to 15 cows,
   and            9 trees + 6 trees add up to 15 trees,
   and            9 cars + 6 cars add up to 15 cars,

so we're pretty sure that

                   9 twelfths + 6 twelfths add up to 15 twelfths.

                     9/12      +    6/12        =        15/12

It wants us to simplify the answer, so
we can divide top and bottom by 3 :

                   15/12  =  5/4  =  1 and 1/4 .