Module 1: Lesson 11

Let's Review!

Let's look at the following problems:

• 31 x 4 = 124

• 3.1 x 4 = 12.4

• 0.31 x 4 = 1.24

How are these problems alike?

• 31 x 4 = 124

• 3.1 x 4 = 12.4

• 0.31 x 4 = 1.24

Now, let's represent them with area models:

• 31 x 4 = 124

• 3.1 x 4 = 12.4

• 0.31 x 4 = 1.24

Now, let's represent them with area models:

31 x 4 = 124

12 tens

​4 ones

​4

​3 tens

1 one

​+

120

​+

4

= 124

Now, let's represent them with area models:

3.1 x 4 = 12.4

12 ones

​4 tenths

​4

​3 ones

1 tenth

​+

12

​+

0.4

= 12.4

Now, let's represent them with area models:

0.31 x 4 = 12.4

12 tenths

​4 hundredths

​4

​3 tenths

1 hundredth

​+

1.2

​+

0.04

= 1.24

Multiplying with Reasonableness (Estimation)

5.1 x 6

Before solving, what would be a reasonable answer?

5.1 x 6

5.1 is close to 5, so we can estimate by multiplying 5 x 6

5.1 x 6

5.1 is close to 5, so we can estimate by multiplying 5 x 6 = 30

5.1 x 6

Now let's solve together...

5.1 x 6 = 30.6

Lesson 11 Problem Set

Multiple Choice

Choose the reasonable product for the expression.

2.5 x 4

• 0.1

• 1

• 10

• 100

Multiple Choice

Choose the reasonable product for the expression.

3.14 x 7

• 2198

• 219.8

• 21.98

• 2.198

Multiple Choice

Choose the reasonable product for the expression.

9 x 5.48

• 493.2

• 49.32

• 4.932

• 4932

Read. Draw. Write

Pedro is building a spice rack with 4 shelves that are each 0.55 meter long. At the hardware store, Pedro finds that he can only buy the shelving in whole meter lengths. Exactly how many meters of shelving does Pedro need? Since he can only buy whole number lengths, how many meters of shelving should he buy?

​0.55 meter
​0.55 meter
​0.55 meter
​0.55 meter

​4 x 0.55

​ .55
x 4
-------

Pedro is building a spice rack with 4 shelves that are each 0.55 meter long. At the hardware store, Pedro finds that he can only buy the shelving in whole meter lengths. Exactly how many meters of shelving does Pedro need? Since he can only buy whole number lengths, how many meters of shelving should he buy?

​0.55 meter
​0.55 meter
​0.55 meter
​0.55 meter

​4 x 0.55

​ .55
x 4
-------
2.20

Pedro is building a spice rack with 4 shelves that are each 0.55 meter long. At the hardware store, Pedro finds that he can only buy the shelving in whole meter lengths. Exactly how many meters of shelving does Pedro need? Since he can only buy whole number lengths, how many meters of shelving should he buy?

​0.55 meter
​0.55 meter
​0.55 meter
​0.55 meter

2.20

Pedro is building a spice rack with 4 shelves that are each 0.55 meter long. At the hardware store, Pedro finds that he can only buy the shelving in whole meter lengths. Exactly how many meters of shelving does Pedro need? Since he can only buy whole number lengths, how many meters of shelving should he buy?

​0.55 meter
​0.55 meter
​0.55 meter
​0.55 meter

2.20

​Pedro will need 3 meters of shelving.

Multiple Choice

Marcel rides his bicycle to school and back on Tuesdays and Thursdays. He lives 3.62 kilometers away from school. Marcel's gym teacher wants to know about how many kilometers he bikes in a week. What should Marcel tell his gym teacher?

• about 14 kilometers

• about 4 kilometers

• about 40 kilometers

• about 400 kilometers

Math Response

Marcel rides his bicycle to school and back on Tuesdays and Thursdays. He lives 3.62 kilometers away from school. Marcel's math teacher wants to know exactly how many kilometers he bikes in a week. What should Marcel tell his math teacher?

Type answer here

Correct Answer: 14.48

Deg^°

Rad

Exit Ticket

Multiple Choice

Use estimation to choose the correct value for the expression

5. 1 x 2

• 1.02

• 10.2

• 102

Multiple Choice

Use estimation to choose the correct value for the expression

4 x 8.93

• 35.72

• 357.2

• 3572

Open Ended

Estimate the answer for 7.13 x 6. Explain your reasoning using words or numbers.