Lesson 3

Pennies and Dimes

Est. Class Sessions: 1–2

Developing the Lesson

Part 1: Partitioning 10 Pennies

Review Partitions of Ten and Fact Families. Using a display of the Ten Frames page from the Student Activity Book Reference section and a display set of pennies, quickly review partitioning ten. Ask students to generate both an addition and a subtraction number sentence to describe the partitions.

As shown in Figure 1, place 7 pennies in the ten frame and ask:

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  • Seven plus what number equals ten? (3)
  • What is the number sentence that describes this?
    (7 + 3 = 10)
  • Now think about fact families. What is a related subtraction number sentence? (10 − 3 = 7)
  • How did knowing about fact families help you find the subtraction number sentence? (Possible response: I know 7 + 3 = 10, so 3 + 7 = 10 is the other addition sentence in the fact family. There are two subtraction sentences, too. 10 − 7 = 3 and 10 − 3 = 7. The same three numbers are used to make all the number sentences.)
  • Is there another way to find the subtraction number sentence? (Possible response: I thought about the ten boxes on the ten frame. 10 is the whole, the biggest number, so I know the other numbers need to be taken away from 10. There were 3 empty boxes and 7 pennies. 10 − 3 = 7.)
  • Show how to use the ten frame to show 6 + 4.
  • Explain how to use fact families to find the related subtraction sentence. (Possible response: 6 + 4 = 10, so 10 − 4 = 6 and 10 − 6 = 4.)

Because of their earlier work, students should be able to recognize all the partitions fairly easily. Comment that even though they are using money, the process is exactly the same. The only difference is that here they are counting pennies, rather than puppies or cookies, etc. Show the cents notation (¢) and explain that this sign signifies that a person is counting pennies. When reading it, they say "cents" as in "10 cents," which means the same as
10 pennies. For example, write 7¢ + 3¢ = 10¢ and 10¢ − 7¢ = 3¢.

Partition 10 Pennies and Write Number Sentences. Direct students' attention to the Pennies section of the Partitioning Pennies and Dimes pages in the Student Activity Book. Distribute a set of ten pennies to each student pair. Tell students that they are going to put the ten pennies into two piles in many ways. Point out that in some of the questions on the page, they will write addition number sentences and in others they will write subtraction sentences to describe the ways they divided the pennies. Remind them to think about fact families and to use the Ten Frames page in the Student Activity Book Reference section.

Adventure Book:
Student Activity Book: 321
Answers
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SAB_Mini
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Master:
Possible number sentences for this ten frame are 10 − 3 = 7 or 7 + 3 = 10
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