Dividing Decimals by Other Decimals Unit 3.7 Pages 126-128

DividingDecimals by

Other Decimals

Unit 3.7 Pages 126-128

1. 4.8 2 =

2. 16.1 7 =

3. 0.36 3 =

4. 25.28 4 =

2.4

2.3

0.12

6.32

Warm Up Problems Divide

What number is the dividend?

76 342045

What number is the divisor?What number is the quotient?

3.7 Dividing Decimals by Decimals.

Objective: by the end of class students can change a divisor with decimals into a whole number and then divide into the dividend to find the quotient.

We follow the same rules for dividing whole numbers, as we divide numbers

with decimals in them.

5 075 5 0.75 0 1 5

- 5 2 5 -2 5

0 1 5

- 5 2 5 -2 5

This time the DIVISOR will

have a decimal in it. We will

need to change it into a whole

number first by moving the

decimal to the right side.

0 7 0 4 2

0 0 6

- 0 4 2 -4 2

Dividing by a Decimal Number

When we changed the divisor to a

whole number we multiplied it

by 10. That is why the decimal

moved from a part of a whole

to a whole

0 7 0 4 2

0 0 6

- 0 4 2 -4 2

Dividing by a Decimal Number

x 10

Now we must multiply the DIVIDEND by 10 too!

When we do this the decimal will

now move to the right 1 space.

x 10

First divide the equation like you normally would.

Count the total number of decimal places in the divisor and move the decimal the same amount of spaces in the dividend.

Place the decimal point directly above in the quotient.

Find each Product 3.6 1.2

1.2 3.6 0 3

-03 6

-3 6 0

=3

First divide the equation like you normally would.

Count the total number of decimal places in the divisor and move the decimal the same amount of spaces in the dividend.

Place the decimal point directly above in the quotient.

Find each Product 7.5 1.5

1.5 7.5 0 5

-07 5

-7 5 0

=5

First divide the equation like you normally would.

Count the total number of decimal places in the divisor and move the decimal the same amount of spaces in the dividend.

Place the decimal point directly above in the quotient.

Find each Product 9.9 1.1

1.1 9.9 0 9

-09 9

-9 9 0

=9

First divide the equation like you normally would.TRY ESTIMATING

DOUBLE DIGIT NUMBERS FIRST!

Count the total number of decimal places in the divisor and move the decimal the same amount of spaces in the dividend.

Place the decimal point directly above in the quotient.

Find each Product 10.5 1.5

1.5 10.5 0 7

-01 0 5

-1 0 5 0

=7

~20

First divide the equation like you normally would.TRY ESTIMATING

DOUBLE DIGIT NUMBERS FIRST!

Count the total number of decimal places in the divisor and move the decimal the same amount of spaces in the dividend.

Place the decimal point directly above in the quotient.

Find each Product 20.4 5.1

5.1 20 4 0 4

-02 0 4

-2 0 4 0

=4

~50

First divide the equation like you normally would.TRY ESTIMATING

DOUBLE DIGIT NUMBERS FIRST!

Count the total number of decimal places in the divisor and move the decimal the same amount of spaces in the dividend.

Place the decimal point directly above in the quotient.

Find each Product 20.4 5.1

5.1 20 4 0 4

-02 0 4

-2 0 4 0

=4

~50

Homework(3.7A) page 131-132

Due: Friday

1-26

Let’s do a few together#1) Find each Product

6.5 1.3 1.3 6.5 0 5

=5

Let’s do a few together#2) Find each Product

20.7 0.6 0.6 20.70

034 5

=34.5

Let’s do a few together#3) Find each Product

25.5 1.5 1.5 25.5 017

=17

Let’s do a few together#4) Find each Product

5.4 0.9 0.9 5.4

0 6

=6

Let’s do a few together#5) Find each Product

2.2 13.2 2.2 13.2

0 6

=6

#6) Find each Product

63.39 0.24

0.24 63.39 0000264 125

=264.125

#7. Marcus drove 354.9 miles in 6.5 hours. On average, how many miles per hour did he drive?

Marcus drove ____ miles/hours?

= 354.9 miles

1 hr 1 hr 1 hr 1 hr 1 hr 1 hr ½

1 hr

Homework(3.7A) page 131-132

Due: FRIDAY!

1-20

Dividingby decimals

Day Two

Unit 3.7 Pages 129-132

#8. Anthony spends $87.75 on shrimp. The shrimp cost $9.75 per pound. How many pounds of shrimp does Anthony buy?

Marcus drove ____ miles/hours?

= $87.75= 1 lb $9.75

What number is the dividend?

76 342045

What number is the divisor?What number is the quotient?What number is the divisor?

*Get into groups of two or three. *Place the number cards face down on the desk. *Pick up 2 cards to be your divisor and 3 cards to be the dividend.

*Take turns placing 2 plastic chips between each number to represent decimals. *Preform the division and share your answers.

3.7 Dividing Decimals by Decimals.

Objective: by the end of class students can change a divisor with decimals into a whole number and then divide into the dividend to find the quotient using powers of 10 and variables.

Substitute the variable for the number given. And divide as

you would with whole

numbers.

n 0.732

012 2 Dividing by using a variable

0.732 n

n=0.06 .06-6 13-12 12 -12

Then divide the equation like you normally would.

Count the total number of decimal

places in the dividend.

Place the decimal point directly above

in the quotient.

# 28 Find each quotient

73.814 c

c 73.814 56 78

Replace the variable with the given

number.

c=1.3 1.3

# 31. 6.35 x 10 0.52

PEMDAS

635 0.5

0.5 6350.

# 32. 8.1 x 10 0.92

PEMDAS

810 0.9

0.9 8100.

Homework(3.7B) page 131-132

Due: Monday

27-36

21.63 2.1

10.3

$3.363.25

6.3

Find each quotient

I spent $13.44 renting 4 videos. What was the

cost per video?

38.43 6.1

16.9 5.2