Multiplying and Dividing Decimals

Multiplying and Dividing Decimals

Let's Review

Multiplying (×) with decimals (using a model)

-Use one color to shade in one number on the model

-Use another color to shade in the other number (in the other direction).

-Where the colors overlap is your answer.

Multiple Choice

Which Equation matches the model?

• 0.4 x 0.2 = 0.8

• 0.6 x 0.1 = 0.06

• 0.2 x 0.4 = 0.8

• 0.2 x 0.4 = 0.08

Multiple Choice

Which answer matches the model?

• The quotient is 24

• The quotient is 0.24

• The product is 24

• The product is 0.24

Multiple Choice

Which Equation matches the model?

• 0.3 x 0.6 = 0.6 x 0.3

• 0.3 x 18 = 18 x 0.3

• 0.18 = 0.18 x 3

• 3 x 6 = 0.3 x 0.6

Multiple Choice

Which Equation matches the model?

• 0.2 x 0.04 = 0.2

• 0.2 x 0.2 = 0.4

• 0.2 x 0.2 = 4

• 0.2 x 0.2 = 0.04

Multiple Choice

Which answer matches the model?

• The product is 80

• The product is 15

• The product is 0.15

• The quotient is 0.15

Multiple Choice

Which equation does this model represent?

• 0.80 x 0.33 = 0.24

• 0.8 x 0.24 = 0.3

• 0.3 x 0.8 = 0.24

• 0.24 x 0.3 = 0.8

Multiple Choice

What expression does this model represent?

• 0.2 x 0.4

• 2x4

• 4x2

• 0.44 x 0.22

Multiple Choice

The hundredths model in the figure is shaded to represent the multiplying of two numbers. Which equation can be represented by the shaded parts of the model.

• 60 x 70 = 4,200

• 0.06 x 0.07 = 0.42

• 0.6 x 0.7 = 0.42

• 0.06 x 0.07 = 0.042

Multiple Choice

Which equation matches this model?

• $0.6\times0.9=$
  

• $0.5\times0.7=$

• $0.9\times0.5=$

• $0.9\times0.4=$

Multiple Choice

Which equation matches this model?

• $0.4\times0.4=$

• $0.3\times0.5=$

• $0.4\times0.3=$

• $0.3\times0.6=$

Multiplying (×) with decimals

• The number with the most digits goes on top

• Decimals do not have to line up

• Multiply like normal

• Count how many places in the first number the decimal is moved over

• Count how many places in the 2nd number the decimal is moved over

• This is how many places you move the decimal in your answer

Multiplying (×) with decimals

• The number with the most digits goes on top

• Decimals do not have to line up

• Multiply like normal

• Count how many places in the first number the decimal is moved over

• Count how many places in the 2nd number the decimal is moved over

• This is how many places you move the decimal in your answer

Multiple Choice

Multiply

 $0.3\times6$  

• 18

• 1.8

• 0.18

• 2.7

Multiple Choice

Solve

 $0.3\times0.5=$  

• 0.15

• 1.5

• 15

• 150

Multiple Choice

Multiply

 $0.7\times0.3$  

• 51

• 2.1

• 0.21

• 0.51

Multiple Choice

Solve

 $0.5\times0.7=$  

• 3.5

• 0.35

• 0.035

• 35

Multiple Choice

Multiply

 $0.2\times0.6=$  

• 1.2

• 0.12

• 0.012

• 12

Multiple Choice

Which model represents the following equation?:

 $0.4\times0.5=0.20$  

Multiple Choice

Which area model represents the following equation?:

 $0.6\times0.4=$  

Multiple Choice

Which area model represents the following equation?:

 $0.8\times0.5=$  

Multiple Choice

Which area model represents the following equation?:

 $0.7\times0.6=$  

Multiple Choice

Which area model represents the following equation?:

 $0.1\times0.7=$