Math Help - Fraction Word Problem

1. Fraction Word Problem

Hi everyone, I have a word problem for a fourth grader. I just can't recall at all what to do:

A group of third graders is asked what their favorite sports are; 1/6 like baseball, 2/3 like hockey, and 12 like football. How many third graders are in the group?

So, $\frac {4}{6} + \frac {1}{6} = \frac {5}{6}$
So, after the baseball and hockey fans, only $\frac {1}{6}$ of the class has yet to answer. They all answer football, so we simply multiply 12 by 6 to get the total class size of 72.