Ethan ate 1/5 of a chocolate bar and gave 1/3 to his friend. if their were 15 pieces in the chocolate bar; how many were eaten in total?

22/18 or 1 4/15

First, you have to find out how many pieces were eaten in all. This could be done with addition. 1/5+1/3= (3/15+5/15)= 8/15

Lastly, you have to find out how much they ate from 15 pieces. This could be done with subtraction. Since 15 is a whole number, the fraction for it would be 15/1. 15/1-8/15=(30/15-8/15)=22/18 or 1 4/15