Lin's grandmother ordered needles that were 0.3125 inches long to administer her medication, but the
pharmacist sent her needles that were 0.6875 inches
long, How much longer were these needles than the
ones she ordered? Show your reasoning.

.375 in

Step-by-step explanation:

Subtract the two numbers.

7 9/14

Step-by-step explanation:

The girls ate 8 1/7 of a pie, so we mark G=8 1/7

The boys ate 1/2 of a pie, so we mark B=1/2

The girls ate the more pies, so we do this:

G-B

We plug the G and the B in, and it is 8 1/7-1/2

We change it to the common denominator, which is 14. We have 8 2/14- 7/14

we take a one and add 14 to 2 and we have this:

7 16/14-7/14

and that equals 7 9/14