Fractions adding and subtracting

Question

Lori is putting together a relay team together to run a race.

She will complete 1/2 of the run. Her friend, Zach will complete 1/10 of the run. If she asks some of her friends to run part of the run, what fraction of the run will each friend need to run?

Use a number line to represent the race and the different distances that were run Justify your thinking.

Answer 1

1 / 2 = 5 / 10

(5 / 10) + (1 / 10) = 6 / 10

4 / 10 of the race remains.

The friends would be asked to make up 4 / 10 or 2 / 5 of the race. How much each one does cannot be stated based on the information.

Answer 2

Hi Sarah,

Let's say that Lori brings 4 more of her friends along with her to complete the remainder of the run.

1/10 + 1/10 + 1/10 + 1/10 = 4/10.

4/10 + 1/10 (the portion of the run that Zach has already completed) = 5/10.

When reduced into lowest terms/simplest form as an equivalent fraction, 5/10 = 1/2.

1/2 + 1/2 = 2/2 = one whole (run).

So, Lori's friends will each need to complete 1/10 of the run.