Lesson 13 Divide Whole Numbers by Unit Fractions

    • Let’s divide a whole number by a unit fraction.

Warm-up Notice and Wonder: Quilt

What do you notice? What do you wonder?

a woman hand-sewing a quilt

Activity 1 Paper Strips

Below are diagrams that show strips of different colored paper. Each strip is 2 feet long. The paper strips will be cut into different sized pieces.

  1. The red strip will be cut into pieces that are foot long. How many pieces will there be?

    Diagram. 2 equal sized parts. 1 part labeled 1 foot. 

  2. The green strip will be cut into pieces that are foot long. How many pieces will there be?

    Diagram. 2 equal sized parts. 1 part labeled 1 foot.

  3. The yellow strip will be cut into pieces that are foot long. How many pieces will there be?

    Diagram. 2 equal parts. 1 part labeled 1 foot.

  4. Describe what was the same about the problems you solved. Describe what was different.

Activity 2 More Paper Strips

Kiran has a yellow strip of paper that is 2 feet long. He wants to cut the strip into pieces that are  foot long.

  1. How many pieces will Kiran have? Explain or show your reasoning.

  2. Write a division equation to represent the situation.

  3. Describe how the equation  represents a strip of paper that is 3 feet long being cut into equal-sized pieces.

Practice Problem

Problem 1

Mai has a strip of paper that is 3 feet long. She cuts it into foot strips.

  1. How many foot strips does Mai make? Explain or show your reasoning.

  2. Write a division equation to represent your answer.