Question

Ashley is on her way home in her car. She has driven 21 miles so far, which is one-third of the way home. What is the total length of her drive?

Answer 1

If 21 miles is 1/3 the distance home, she must drive 3x the distance to get home.

21x3=63 miles

The total length of her drive is 63 miles.

Another method is to write an equation, with d being the total distance:
21=1/3d
(3)21=1/3d(3)
63 miles=d

Answer 2

So if 21 miles is 1/3 of the way you want to multiply 21 by 3 to get 3/3 or the whole way.

21*3=63

The total length of her trip was 63 miles.