Given:
3 dozen oatmeal cookies
1/6 of them was eaten
How many was left?
1 dozen is equal to 12 pieces.
3 dozen * 12 = 36 pieces
36 * 1/6 = 36/6 = 6
Stacy ate 6 pieces of oatmeal cookies.
36 - 6 = 30 pieces left.
There are 30 pieces of oatmeal cookies left.