Gallon, quart and pint are volume units. Think of a gallon of milk, a pint of beer, etc. 4 quarts make a gallon and 2 pints make a quart.
List out the addition problem.
1 gallon + 3 quarts + 2 quarts + 3 pints
combine like amounts
1 gallon + 5 quarts + 3 pints
Start with the smallest size (pints) and change to larger size unit if possible.
Remember:
2 pts = 1 qrt
4 qrt = 1 gal
1 gallon + 5 quarts + 3 pints
*The 3 pints becomes 1 quart + 1 pint
1 gallon + 5 quarts + 1 quart + 1 pint
1 gallon + 6 quarts + 1 pint
* 4 quarts make a gallon, since there's 6 qrts = 1 gal + 2 qrts
2 gallon + 2 quarts + 1 pint
