Inches, feet, yards, and cubes

Memorize three conversions. 12 inches in a foot. 3 feet in a yard. 27 cubic feet in a cubic yard.

The cubic one is the one people miss. A yard is 3 feet, so a cubic yard is 3 × 3 × 3, not 3. A square yard is 3 × 3 = 9 square feet, which is another trap if the question says cubic.

For a mixed length such as 5 feet 4 inches, convert the feet first, then add the inches: 5 × 12 + 4 = 64. Shop mixes also use 4 quarts in a gallon and 16 ounces in a pound.