The art class had a box filled with balls of yarn. the student used six and two thirds balls for a project. there are now two and two thirds left in the box. How many balls of yarn did the art class start with

What you must do in this case is to add the number of yarn balls that the student used with the number of yarn balls that were left in the box.

Adding we have:

(6 2/3) + (2 2/3) = 8 4/3 = 9 1/3

answer

the art class start with 9 1/3 balls of yarn