Lesson 5: Fraction Division Problem Solving6.NOS.1

I can…

I can solve real-world problems by writing and solving fraction division equations.

Key words

• Model — A picture or math way to show a problem so you can solve it.
• Equation — A math sentence with an equal sign showing both sides are the same.
• Solution — A number that makes the equation or inequality true.
• Reasonableness — Checking if your answer makes sense.
• Inverse operations — Two math actions that undo each other, like × and ÷.

Steps

1. Agent Torres has 2/3 gallon of dust and each test uses 1/6 gallon. I ask: how many tests fit?
2. The total 2/3 is the dividend. The size of each test 1/6 is the divisor. My equation is 2/3 ÷ 1/6.
3. Keep 2/3, change to ×, flip 1/6 to 6/1: 2/3 × 6/1 = 12/3 = 4.
4. So she can run 4 tests. I check by multiplying back: 4 × 1/6 = 4/6 = 2/3. It matches the total, so the answer is reasonable.

Try it

A pipe is 3/4 meter long. Each connector piece is 3/8 meter. How many connectors fit on the pipe?

Check your answer

2

3/4 ÷ 3/8 = 3/4 × 8/3 = 24/12 = 2. Two connector pieces fit on the pipe.

Sentence starter

I know ___ because ___.

Goal: I can explain my reasoning using the words model, equation, solution, and reasonableness.