Question

Cate and Elena were playing a card game. The stack of cards in the middle had 24 cards in it to begin with. Cate added 8 cards to the stack. Elena then took 12 cards from the stack. Finally, cate took 9 cards from the stack. How many cards were left in the stack?

Answer 1

You start with 24, there are 8 added, there are 12 taken away, then 9 are taken away. The equation looks like:
24 + 8 - 12 - 9 = 11