Section A: Practice Problems What is Division?

Section Summary

Details

In this section, we learned that division is finding the number of groups or finding the size of each group when we put objects into groups of equal size. We represented division situations with drawings and expressions, and solved division problems.

“How many groups?”

“How many in each group?”

Han has 12 colored pencils. He wants to put 2 colored pencils in each box until he’s out of colored pencils. How many boxes does Han need?

Elena has 12 colored pencils. She has 2 boxes and wants to put the same number of colored pencils in each box. How many pencils will be in each box?

6 groups of 2 dots.

2 groups of 6 dots.

Problem 1 (Pre-Unit)

Array. 4 rows of 5 dots.

  1. Write a multiplication expression that represents the array.

  2. Write a multiplication equation that represents the array.

Problem 2 (Pre-Unit)

Find the area of each rectangle.

  1. Area diagram.
  2. A rectangle. Left side labeled 4 centimeters. Top labeled 10 centimeters. Other sides unlabeled.

Problem 3 (Pre-Unit)

The area of the rectangle is 40 square centimeters.

Find the missing side length of the rectangle. Explain your reasoning.

A rectangle. Left side labeled 5 centimeters. Top labeled question mark. Other sides unlabeled.

Problem 4 (Pre-Unit)

Find the number that makes each equation true.

Problem 5 (Pre-Unit)

There are 6 volleyball teams in the gym. Each team has 10 players. How many volleyball players are there altogether?

  1. Make a drawing of the situation.

  2. Write an equation with a “?” for the unknown that represents the situation.

  3. Solve the problem.

Problem 6 (Lesson 1)

For each problem, show your thinking using a drawing or a diagram.

  1. There are 40 apples packed into boxes. If there are 8 apples in each box, how many boxes are there?

  2. There are 40 apples packed into boxes. If there are 10 apples in each box, how many boxes are there?

Problem 7 (Lesson 2)

For each problem, show your thinking using a drawing or a diagram.

  1. There are 30 oranges. If they are packed into 5 bags with the same amount of oranges in each bag, how many oranges are in each bag?

  2. There are 30 oranges. If they are packed into 3 bags with the same amount of oranges in each bag, how many oranges are in each bag?

Problem 8 (Lesson 3)

  1. 10 people go to the movies in cars. Two people go in each car. How many cars are there? Show your thinking using a drawing or a diagram.

  2. 10 other people go to the movies in cars. They ride in 2 cars with the same number in each car. How many people are in each car? Show your thinking using a drawing or diagram.

  3. How are the two situations the same? How are they different? How are the diagrams the same? How are they different?

Problem 9 (Lesson 4)

There are 20 desks in the class. They are divided equally into 5 groups. How many desks are in each group?

  1. Which expression represents this situation: or ? Explain your reasoning.

  2. Choose the diagram that represents this situation. Explain your reasoning.

    A
    4 groups of 5 dots.
    B
    5 groups of 4 dots.

Problem 10 (Lesson 5)

Mai’s family picked 40 pounds of peaches. They put 5 pounds in each bag.

  1. Write a division expression that represents the situation.

  2. How many bags of peaches did Mai’s family pick? Explain or show your reasoning.

Problem 11 (Exploration)

Complete each story by putting a number in the blank that makes sense. Then, answer the questions. Draw a diagram to solve each problem.

  1. Mai has stickers. She is going to put the same number of stickers on each of her 5 notebooks. How many stickers will be on each notebook?

  2. Andre has cards. He is going to arrange them in rows of cards. How many rows will Andre’s cards make?

Problem 12 (Exploration)

Write a division situation to match each diagram.

  1. 2 groups of 7 dots.
  2. 9 groups of 3 dots.
  3. 6 groups of 4 dots.