Question

Susanna found a roll of fabric she wanted to use to make a pillow. The roll had 3/4 of a yard of fabric left. Susanna needed 5/8 of the remaining fabric. Which fraction represents how much fabric Susanna needed?

Answer 1

1/8

Explanation:

3 /4 − 5 /8

We can't subtract two fractions with different denominators. So you need to get a common denominator. To do this, you'll multiply the denominators times each other... but the numerators have to change, too. They get multiplied by the other term's denominator.

So we multiply 3 by 8, and get 24.

Then we multiply 5 by 4, and get 20.

Next we give both terms new denominators -- 4 × 8 = 32.

So now our fractions look like this:

24 /32 − 20 /32

Step 2

Since our denominators match, we can subtract the numerators.

24 − 20 = 4

So the answer is:

4 /32

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

4 /32 ÷ 2 =2 /16

2/ 16 ÷ 2 =1 /8

2 is larger than 1. So we're done reducing. There you have it! The final answer is:

3 /4 - 5 /8 = 1 /8