Simon has two identical aquariums. There are $$26$$ quarts of water in one, and $$42$$ quarts of water in the other. How many quarts of water does Simon need to pour from the second aquarium into the first in order to have the same amount of water in both? 
Overseas Competition->Knowledge Point->Word Problem Modules->Average Problems ->Giving and Receiving
Difference: $42-26=16$  Move: Half of $16=8$ 