8.6 Choosing a Multiplication Strategy

8.6 Choosing a Multiplication Strategy

Students will fluently multiply two 2-digit numbers using the method of my choice.

Standard

4.NBT.B.5: Multiply a whole number of up to four digits by a one-digit whole number, and multiply two two-digit numbers, using strategies based on place value and the properties of operations. Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models.

Most professional soccer matches require 14 soccer balls. The traditional soccer ball has 32 panels, each representing one country in Europe.

Multiple Select

What are the two factors you would use to figure out how many panels are on 14 soccer balls with 32 panels each?

• 2

• 7

• 14

• 32

Open Ended

What strategy would you use to figure out how many patches are on 14 soccer balls?

Fill in the Blanks

14 x 32=

At the beginning of each season, the National Basketball Association sends each of the 29 American teams 72 basketballs.

The next few problems will explore this.

Multiple Select

What factors do you use to find out how many basketballs each team has?

• 1

• 20

• 29

• 72

Open Ended

What strategy would you use to figure out how many basketballs all the teams have together?

How can you multiply one factor by the ones and by the tens of the other factor?

Multiply 72 by  __________ ones.

Multiply 72 by  __________ tens.

Fill in the Blanks

Multiply 72 by

ones.

Fill in the Blanks

72 x 9 =

Fill in the Blanks

Multiply 72 by

tens

Fill in the Blanks

72 x 20 =

Fill in the Blanks

648 + 1,440=