Dividing Decimals PPT

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Transcript Dividing Decimals PPT

Bell Work September 9 
1. Carpeting costs $7.99 a yard. If Jan
buys 12.4 yards, how much will it cost
her?
2. Jackie just bought a new car. Use the
information in the picture to find out how far
she will get on the highway before she runs
out of gas and has to call a tow truck.
Parts of a Division Problem:
15
5 75
divisor
quotient
dividend
Parts of a Division Problem with
decimals
Quotient
0.15
5 0.75
Divisor
Dividend
• How do we divide with decimals?
3.6 Dividing Decimals
EQ: How do you solve
problems involving the addition,
subtraction, multiplication, and
division of decimals?
(SPI: 0606.2.3) /CC.6EE.2b
To divide a decimal by a
whole number move the
decimal point straight up
and then divide as usual
Modeling .35 ÷ 7
Example 1
5 7.5
Terminating decimal is a decimal
number that ends, or
terminates in the quotient.
Let’s do a few together
8 27.2
Find the quotient.
0.24
3 0.72
0.72 ÷ 3
No more remainders……what will we do?
130 ÷ 20
Showing the Remainder as a
Decimal.
6 .5
20 130.0
-120
100
-100
Place the decimal
point in the quotient
above the decimal
point in the dividend.
Add a zero to the
dividend.
Continue dividing.
You try this….
2÷3
Repeating decimal is a decimals that
one or more numbers repeat.
Now you try.
Hint: You may need to add more than one zero!
4 37
8 12.6
5. At a fruit stand, 8 pounds of apples cost
$2.80. Identify the average cost of apples
per pound.
A. $35.00
B. $3.50
C. $0.35
D. $0.03
How well do you understand dividing decimals?
.
I don’t
understand
I nearly
understand
I fully
understand
Ticket out the Door
Find each quotient.
1. 3.12 ÷ 8
0.39
2. 5.68 ÷ 8
0.71
Evaluate the expression 1.25 ÷ x for the given
value of x.
3. x = 5 0.25
4. x = 25 0.05
5. The tennis team is having 3 of their tennis
rackets restrung. The total cost is $54.75. What is
the average cost per racket? $18.25
3.6 Dividing Decimals
EQ: How do you solve
problems involving the addition,
0011 0010 1010 1101 0001 0100 1011
subtraction, multiplication, and
division of decimals?
1
(SPI: 0606.2.3) /CC.6EE.2b
2
4
3-7 Dividing Decimals by a
Decimal
I CAN divide with a
decimal in the divisor
Review from yesterday…..
Divide.
1. 4.8 ÷ 2
2. 16.1 ÷ 7
2.4
2.3
3. 0.36 ÷ 3
0.12
4. 25.28 ÷ 4
6.32
Composition Notes
Ex 1: Divide by a whole number
2.35 ÷ 5
Ex 2: Divide by a decimal number
6.85 ÷ .5
Ex 3: Add a decimal and zeros
3764 ÷ 6
• To divide a decimal by a decimal move the decimal point
in the divisor over to make a whole number.
• Then you move the same amount of spaces in your
dividend.
1.35 ÷ .45
Find the quotient.
5.2 ÷ 1.3
1.3 5.2
Multiply the divisor and dividend by
the same power of ten.
4
13 52
–52
0
5.2 ÷ 1.3 = 4
1. Identify the quotient.
72  0.9
A. 70
B. 79
C. 80
D. 90
You try this….
Find each quotient.
1. 49 ÷ 0.7
2. 21.63 ÷ 2.1
3. 38.43 ÷ 6.1
4. 16.9 ÷ 5.2
5. John spent $13.44 renting 4 videos for the
weekend. What was the cost per video?
6. After driving 191.1 miles, the Changs’ used
10.5 gallons of gas. On average, how many
miles did they drive per gallon of gas?
3-7 Dividing Decimals by a
Decimal
SPI 6.2.3
I CAN divide with a
decimal in the divisor!!
Review What We Know
• Turn to your shoulder partner one
person go over all the steps for dividing
when the decimal is in the dividend.
– What do you do with the decimals
• Other partner go over all the steps when
dividing if the decimals is in the divisor.
• Together discuss the difference and
similarities between both.
• 27 ÷ .9
• 15 ÷ .05
2. Identify the quotient.
36.12  4.2
A. 8.6
B. 8.8
C. 9.5
D. 9.6
0.36 61.30
Quiz
Answer the following on a separate sheet of paper
1. 4.8 ÷ 2
2. 25.28 ÷ 4
3. 62.4 ÷ 0.5
2.4
6.32
124.8
4. 13.44 ÷ 0.4 33.6
5. 4.32 ÷ 1.2 3.6
How well do you understand dividing decimals?
.
I don’t
understand
I nearly
understand
I fully
understand