If Aron has 2 pizzas left from the sleepover, and he ate 1/8 of one pizza, that means he ate:
1/8 * 1 = 1/8 of a pizza
So he ate 1/8 of a pizza.
To find out how much pizza is left, we need to subtract the amount that he ate from the total amount of pizza. If he started with 2 pizzas and ate 1/8 of one pizza, that means there are:
2 - 1/8 = 15/8
So there are 15/8 (or 1 and 7/8) pizzas left