There are 26 cards in a box. bryan takes 12 cards. how many cards are still in the box

14 cards in the box left

We can use a simple word equation to represent this.
# of cards left in the box = # of cards in the box - # taken out of the box 

# of cards in the box: 26
# taken out of the box: 12

This means:

# of cards left in the box = 26 - 12

26 - 12 = 14

So, 14 cards are still in the box.