Putting the Pieces Together

Multiplication with Base 10

Model the following problems using base ten blocks or quick pics.

3 x 14

4 x 21

12 x 23

Grade 4 In grade four, students extend multiplication and division to include whole numbers greater than 100. Students should use methods they understand and can explain to multiply and divide. The standards call for students to use visual representations such as area and array models that students draw and connect to equations, as well as written numerical work, to support student reasoning and explanation of methods. By reasoning repeatedly about the connections between math drawings and written numerical work, students can come to see multiplication and division algorithms as abbreviations or summaries of their reasoning about quantities.

-California Mathematics Framework Grade 4 p. 14

Arrays

Section J in the arena has 20 rows. Each row has 5 seats. How many seats are there in Section J?

• Create a model to represent this problem using Base 10 blocks.

• Draw what you modeled with Base 10 using an area model.

Area Model

Let’s try it….

Model the following problems using the area model.

25 x 15

42 x 37

Table Talk

• Discuss the connection between how your table solved the problems and the framework.

Partial Products

Multiplication with Partial Products

57 x 42

50

7

40 2

50 x 40 = 2000 50 x 2 = 100

7 x 40 = 280 7 x 2 = 14

57 X 42 14 (7x2)

100 (50x2)

280 (40x7)

2000 (40x50)

2394

Let’s try it….

Model the following problems using partial products. Pick one and solve using an area model as well.

25 x 15

42 x 37

34 x 28

Table Talk

• Discuss the connection between how your table solved the problems and the framework.

36 x 24

Application

On YELLOW

Application

On PINK

Application

On BLUE

Connection to SMPs

• SMP.4 Model with mathematics.

• SMP.5 Use appropriate tools strategically.

• SMP.8 Look for and express regularity in repeated reasoning.

Putting the Pieces Together