Use this calculator to easily multiply a number consisting of feet, inches, and a carpenter fraction by a factor that could be a decimal value.
Multiplying a value represented by feet, inches and carpenter fractions involves reducing everything down to decimal inches. They are much easier too handle. In other words, 10′ 5 1/2″ would be represented as 125.5. This make everything click with the computer much easier.
Two add mixed numbers like this, they must first be converted to manageable form; such as an integer followed by a decimal value. In other words, apples can not be multiplied by bananas unless they are of equal value.