Sara builds a birdhouse that is 1 foot wide, 2 feet tall and 2 feet deep. Jake builds a birdhouse that is 16 inches wide, 20 inches tall and 18 inches deep. What is the difference in volume between the two birdhouses? Think carefully first, then make a decision:
To compare volumes, the measurements must be in the same units. There are 12 inches in 1 ft, so Sara’s birdhouse is 1 ft x 12 inches / ft = 12 inches wide, 2 ft x 12 inches / ft = 24 inches tall, and 2 ft x 12 inches / ft = 24 inches deep. The volume of Sara’s birdhouse is 12 inches x 24 inches x 24 inches = 6,912 cubic inches. The volume of Jake’s birdhouse is 16 inches x 20 inches x 18 inches = 5,760 cubic inches. The difference between the two birdhouses is 6,912 cubic inches – 5,760 cubic inches = 1,152 cubic inches. So, the answer is 1152.