add or subtract
4 red ships and 4 blue ships land at the harbor. If you want to put a flag on each ship, how many flags would you need.
8 flags
Jim had 9 candles. Last night, he used 5 candles when the power went out. How many candles does Ken still have?
4 candles
There are 7 umbrellas in the hall. 3 of them are broken. How many umbrellas still work?
4 umbrellas
There are 9 eggs. If you eat 3 eggs, how many eggs will you have left to eat?
6 eggs
There were 10 fish in the pond. After you gave 2 fish to your friend how many fish remain in the pond?
8 fish