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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
