Eighty inches divided by 12 inches per foot equals 6.67 feet. This is equal to 6 full feet and a remainder of two-thirds of a foot. Twelve inches per foot multiplied by two-thirds of a foot equals 8 inches, so 80 inches is equivalent to 6 feet 8 inches.
The imperial system of length used in the United States has units such as inches, feet and yards that can be used to provide accurate measurements. Six feet 8 inches, for example, can also be written in terms of yards. Six feet divided by 3 feet per yard equals 2 yards 8 inches.