Add 3 feet 6 inches plus 8 feet 2 inches plus 4 inch

Question

Add 3 feet 6 inches plus 8 feet 2 inches plus 4 inches plus 2 feet 5 inches

Answer 1

Well then total of the inches is 8+2+4 = 12 inches which is really 1 foot, so 1 foot gets carried over.

THe total feet including the carry is 3 + 8 + 1 = 12

so 12 feet exactly