Rusty's hair grows at the rate of 1 over 4 inch per month. how many months will it take rusty's hair to grow 5 over 8 inch? explain your answer using words, and show your work using division of fractions.

It will take Rusty's hair 2 1/2 months to grow 5/8 inches.

I know that if Rusty's hair grows 1/4 inch per month, it will grow 1/2 or 2/4 inch in 2 months because 1/4 times 2 is 1/2.  In three months, it will grow 3/4 inches. 5/8 is halfway between 1/2 (4/8) and 3/4 (6/8).  So, his hair needs to grow another eighth at two months.  1/4 divided by 2 equals 1/8, so do the same thing with a month.

First step is to get the same denominator.
5/8 is the same as 2.5/4 of an inch.
1/4m=2.5/4 ->m being months
m=2.5
2 1/2 months