Lesson 4

Pocket Parts

Est. Class Sessions: 2

Developing the Lesson

Part 2: Combining Three Parts and Finding the Whole

Use the Shirts, Pants, and Coat Pockets Master to create and display problems for the class involving three addends.

Display a problem similar to the following and discuss:

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  • Linda is wearing a shirt that has 1 pocket, pants that have 4 pockets, and a coat that has 2 pockets. How many pockets is Linda wearing?
  • What strategies or tools did you use to solve this problem?

Identify a variety of strategies and tools (e.g., number line, connecting cubes, and ten frames) students are using and identify students to share these strategies with the class. Display and refer students to the Math Practices page in the Student Activity Book Reference section. Direct students to Math Practices Expectation 5, Show my work. Ask the identified students to demonstrate and explain their solution strategy for this problem. Display the number sentence for the three addends and the solution to this problem. Redirect the discussion as needed to encourage students to use the counting-on strategy. See Sample Dialog 2.

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Use this Sample Dialog to guide student discussion of the counting-on strategy for addition.

Teacher: Good, John. I see you used the number line by starting at zero and hopping to 1, showed 4 more hops, then 2 more hops, and ended on 7. I see 7 hops to show the total. How can you use counting on to show the total on the number line?

John: Well, I could start at 4 because that's the biggest number of pockets, count on with a 2 jump then a 1 jump instead of starting at zero and hopping by ones. I still have 7 total.

Teacher: Which seemed easier to you?

John: The counting on way because instead of 7 little hops I started at the biggest number then just added 2 more jumps that matched the other two numbers and still had the same total.

Pose and discuss several other problems. Encourage students to use the counting-on strategy when appropriate rather than counting from one. Write number sentences to represent each solution.

After several examples, ask students to complete the How Many Pockets? pages in the Student Activity Book. Circulate among students while listening to their solution strategies. After they have completed all the problems, ask each student to choose one problem to explain to their partner. Students should take turns describing what they did to solve the problem. These rehearsals help students clarify their thinking and become better at explaining their strategy.

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Ask students to record their solution to a problem from the How Many Pockets? pages in the Student Activity Book using a video or audio recorder. Students can then listen to their recording and re-record it until they are satisfied with their explanation. These recordings also provide evidence to monitor student growth or make instructional choices.

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Use the How Many Pockets? pages in the Student Activity Book to assess students' abilities to explain their solutions so someone else can understand their thinking [MPE5].

Adventure Book:
Student Activity Book: 47 48
Answers
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SAB_Mini
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SAB_Mini
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Master: