How could I use unit multipliers to solve this...?

Question

I need to use TWO unit multipliers to change 90 square feet to square inches.

can anyone please explain this to me?

Answer 1

A unit multiplier is a ratio of two numbers that equals 1. So, if you start with the statement:

1 foot = 12 inches and divide both sides by 1 ft, you have:

12 in/1 ft= 1. This is a unit multiplier.

So, to covert 90 square ft to square inches, you woul do the following:

90 ft^2 (12 in/1 ft) (12 in/1 ft) = 12960 in^2