Student Help Card

Lesson 4: Divide Mixed Numbers6.NOS.1

Stuck? Start here. Read the steps, try the problem, then check your answer.

I can…

I can divide mixed numbers by first changing them to improper fractions.

Mixed Number — A whole number plus a fraction, like 2 1/3.
Improper Fraction — A fraction where the top is bigger than or equal to the bottom, like 7/4.
Convert — To change a number to a new form but keep the same value.
Simplify — To make a fraction smaller using the same parts, like 2/4 = 1/2.
Reciprocal — A fraction turned upside down. You use it in keep-change-flip.

Agent Chen has a 3 1/2-mile route cut into 1/4-mile segments. I want 3 1/2 ÷ 1/4.
First I convert 3 1/2. Multiply the whole by the bottom: 3 × 2 = 6. Add the top: 6 + 1 = 7. So 3 1/2 = 7/2.
Now Keep, Change, Flip: keep 7/2, change ÷ to ×, flip 1/4 to 4/1.
Multiply: 7/2 × 4/1 = 28/2.
Simplify: 28/2 = 14. So 3 1/2 ÷ 1/4 = 14 segments.

What is 2 2/3 ÷ 2/3?

2 2/3 = 8/3. Then 8/3 ÷ 2/3 = 8/3 × 3/2 = 24/6 = 4.

I know ___ because ___.

Goal: I can explain my steps using the words mixed number, improper fraction, convert, reciprocal, and simplify.