There are two aquariums in a science room. one of the aquariums is 18 inches wide, 25 inches long, and 12 inches high. if there are 231 cubic inches in a gallon, how many gallons of water can the aquarium hold

First, you have to find the volume of the aquarium. Since the aquarium is a rectangular prism, the formula for the volume is lwh.
L= 15, W=18, and H= 12.
15 x 18 = 270 270 x 12 = 3,240
Second, since there are 231 cubic inches in a gallon, we have to divide our 3,240 by 231. 
3,240 divided by 231 = 14.025974.
Now, we just round it down to 14 gallons.
The aquarium can hold 14 gallons of water.