MultiplyingDecimals

Unit 3.5 Pages 126-128

1. 87 x 320 =

2. 943 x 800 =

3. 3,806 x 10 =

27,840

754,400

38,060

Warm Up Problems Multiply

3.5 Multiplying Decimals.

Objective: by the end of class students can multiply whole numbers and numbers with decimals.

We follow the same rules for multiplying whole numbers, as we multiply numbers

with decimals in them.

258 x 37

2.58x 3.7

9546 9 5 46

The total number of

decimal places in the equation

will need to equal the total

number or decimal places in the solution.

2.58x 3.7 9.546

2 places

1 place

3 places total

Showing the same equation in fractions can help us understand how we come up with a solution.

3.7 x 2.58 37 x 25810 100

= 9546 1,000= 9.546

First multiply the equation like you normally would.

Count the total number of decimal places in the problem.The product (or answer) needs to have the same number of decimal places too.

Find each Product 3 x .17

0.17x 30 51

First multiply the equation like you normally would.

Count the total number of decimal places in the problem.The product (or answer) needs to have the same number of decimal places too.

Find each Product 0.2 x 0.6

0.2x 0.60 12

First multiply the equation like you normally would.

Count the total number of decimal places in the problem.The product (or answer) needs to have the same number of decimal places too.

Find each Product 3.25 x 4.8

3.25x 4.8

15 600

First multiply the equation like you normally would.Count the total

number of decimal places in the

problem.The product (or

answer) needs to have the same

number of decimal places too.

0.6 x 0.4

0.6x 0.4

0.24

#3 find each product

First multiply the equation like you normally would.Count the total

number of decimal places in the

problem.The product (or

answer) needs to have the same

number of decimal places too.

0.008 x 0.5

0.008x 0.5

0.0040

#4 find each product

First multiply the equation like you normally would.Count the total

number of decimal places in the

problem.The product (or

answer) needs to have the same

number of decimal places too.

3.0 x 0.07

3.0x 0.07

0.21

#5 find each product

First multiply the equation like you normally would.Count the total

number of decimal places in the

problem.The product (or

answer) needs to have the same

number of decimal places too.

0.12 x 0.6

0.12x .06

0.0072

#6 find each product

multiply the equation like you normally

would.

Count the total number of decimal places in the

problem.

The product (or answer) needs to have

the same number of decimal places too.

Evaluating decimal Expressions

x= 4.047

3 x4.047

Replace the variable with the given number.

4.047x 312 141

multiply the equation like you normally

would.

Count the total number of decimal places in the

problem.

The product (or answer) needs to have

the same number of decimal places too.

Evaluating decimal Expressions

x= 2.95

3 x2.95

Replace the variable with the given number.

2.95x 3 8 85

First multiply the equation like you normally would.Count the total

number of decimal places in the

problem.

The product (or answer) needs to

have the same number of decimal

places too.

x= 3.304

3.304x 5

16.52

#7 Evaluate 5x Replace the variable with the given

number.

x

First multiply the equation like you normally would.Count the total

number of decimal places in the

problem.

The product (or answer) needs to

have the same number of decimal

places too.

x= 7.126

7.126x 5

35.63

#8 Evaluate 5x Replace the variable with the given

number.

x

First multiply the equation like you normally would.Count the total

number of decimal places in the

problem.

The product (or answer) needs to

have the same number of decimal

places too.

x= 4.58

4.58x 5

22.90

#8 Evaluate 5x Replace the variable with the given

number.

x

First multiply the equation like you normally would.Count the total

number of decimal places in the

problem.

The product (or answer) needs to

have the same number of decimal

places too.

x= 1.9

1.9x 5

9.5

#10 Evaluate 5x Replace the variable with the given

number.

x

3.5 Homeworkpage 124-125

Due:

8-29Mrs. Saucedo’s Class

14-29

0.8 x 0.07 0.006 x 0.07

0.056

6.43221.64

0.00042

Find each product

8x x = 2.705

8x x = 0.804