Lesson 3

Birthday Party

Est. Class Sessions: 2

Summarizing the Lesson

Use a display of the Ice Cube Problem Master to pose the problem below. Cover the sample solutions.

Ask:

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  • Frank helped his mother get ready for a party. He had 33 ice cubes to put into cups. If he put six ice cubes in each cup, how many cups did he fill?

Before students begin their work refer them to the Math Practices page in the Reference section of the Student Guide. Ask students to read Math Practice Expectations 2, 5, and 6. Explain that they should think about these Expectations as they are working on their solutions.

Ask:

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  • What tools or strategies can you use to help you solve this problem? (Possible response: I can use counters, drawings, a number line, number sentences, and words.)
  • What do you need to include in your explanation so that others can understand your thinking? (Possible response: You need to show the steps you took to solve the problem using pictures, numbers, and words. You need to include labels to show what the numbers and pictures mean.)

Tell students that their explanations should be clear, but that they do not need to be lengthy.

Ask students to work in pairs to solve the problem and then show or tell their solution path.

After students have solved the problem themselves, show the questions and sample student work on the display. These solutions are in Figure 3. Ask students to discuss them with their partners using the Math Practices page and questions on the display. When students have had enough time to consider each solution, discuss the questions as a class. Use Sample Dialog 2 as a guide for this discussion.

Have students share their solutions with the class. Use prompts similar to those in the Sample Dialog. Encourage students to ask clarifying questions of one another. If students use number sentences, ask them to explain what each symbol means.

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Use the following dialog to guide a discussion of the Ice Cube Problem Master and Math Practices 2, 5, and 6.

Teacher: How do you think Nisha solved the problem?

Kim: Nisha first counted by 6s until she reached 30 and then added 3. That wasn't too clear, but I think that is what she did. Then she thought about it as a division problem because she wrote a division number sentence.

Teacher: I think so, too. What do each of the numbers in the division number sentence stand for?

Kim: The 33 is for all the ice cubes. The 6 is for the ice cubes in each cup. The 5 is for the number of cups and R3 shows that 3 are left over.

Teacher: 3 ice cubes or 3 cups?

Kim: 3 ice cubes.

Teacher: What would have helped you understand her solution better?

Mark: If she put labels and if she explained the sixes and the 3.

Teacher: What was Sam thinking when he solved the problem?

Chris: He was thinking multiplication. He probably remembered that 6 times 5 is 30. So, after he put 6 ice cubes in 5 cups to use up 30 ice cubes…

Luis: He forgot the last 3 ice cubes.

Teacher: That's right. How could he fix that?

Luis: He could do like Jason and write a subtraction sentence to show the 3 left over.

Teacher: What did they all forget to do?

Luis: Label their numbers.

Student Guide: REF
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SG_Mini
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Student Activity Book:
Master:
Sample student solutions to the Ice Cube Problem
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