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DECIMALSRounding Decimals Review
andMultiplying Decimals
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___ , ___ ___ ___ ___ ___ ___ ___
Th
ou
san
ds
Hu
nd
red
s
Ten
s
On
es
Ten
ths
Hu
nd
red
ths
Th
ou
san
dth
s
Ten
Th
ou
san
dth
s
5 1 8 2 1
Read as 518 and 21 hundredths
Decimals are read as “and” Rounding Review
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Find the number. Circle it.Look next door.4 or less just ignore.5 or more add one more.Example: Round 5368 to nearest hundreds.
Circle the 3 in the hundreds place. Look next door at the 6.
It is 5 or more so add 1 more to the hundreds place.
5368 rounds to 5400
Rounding Review
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Round to the nearest tenths
2.876
2.9
Round to the nearest hundredths
31.6999
31.70
Rounding Review
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Round to the nearest tenths
3.478
3.5
Round to the nearest hundredths
22.5972
22.60
Rounding Review
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Steps for Multiplying Decimals
Step 1: Write the problem vertically.Step 2: Ignore the decimal point(s) and multiply.
Step 3: Determine where the decimal point goes in the product.
Place the decimal point in the answer by counting how many places the decimal point has moved.
Multiplying Decimals
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Multiply 3 x 0.14
0.14 3 x 0.14
=
0.42
Multiplying Decimals
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Multiply 3 x 0.14
2
Step 1: Write the problem vertically 0.14
x 3 Step 2: Ignore the decimal points and multiply
Step 3: Determine where the decimal point goes in the product.
The decimal moves two places to the left
1
40
0.42
Multiplying Decimals
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Multiply 5 x 0.18
0.18 5 x 0.18
=
0.90
Multiplying Decimals
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Multiply 5 x 0.18
0
Step 1: Write the problem vertically 0.18
x 5 Step 2: Ignore the decimal points and multiply
Step 3: Determine where the decimal point goes in the product.
The decimal moves two places to the left
4
90
0.90
Multiplying Decimals
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Multiply 0.2 x 0.6
0.2 0.6
=
0.2
Multiplying Decimals
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Multiply 0.2 x 0.6
0.2 0.6
=
0.2 x 0.6
Multiplying Decimals
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Multiply 0.2 x 0.6
0.2 0.6
=
0.2 x 0.6= 0.12
Multiplying Decimals
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Multiply 0.2 x 0.6
2
Step 1: Write the problem vertically 0.2
x 0.6 Step 2: Ignore the decimal points and multiply
Step 3: Determine where the decimal point goes in the product.
The decimal moves two places to the left
10
0. 12
Multiplying Decimals
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Multiply 0.4 x 0.7
0.4 0.7
=
0.4
Multiplying Decimals
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Multiply 0.4 x 0.7
0.4 0.7
=
0.4 x 0.7
Multiplying Decimals
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Multiply 0.4 x 0.7
0.4 0.7
=
0.28
Multiplying Decimals
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Multiply 0.4 x 0.7
8
Step 1: Write the problem vertically 0.4
x 0.7 Step 2: Ignore the decimal points and multiply
Step 3: Determine where the decimal point goes in the product.
The decimal moves two places to the left
20
0. 28
Multiplying Decimals
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Multiplying Decimals200
x .250+
50000
001004
Move the decimal two places
to the left in your answer.
.
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Multiplying DecimalsHOW MANY DECIMAL PLACES?
1 decimal place3.1
2) (0.4)(2.53)0.4
2.53
1) 3.1(0.28)
1.012
0.28 2 decimal places0.868 1 + 2 = 3 decimal
places1 decimal place2 decimal places1 + 2 = 3 decimal places
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Multiplying Decimals1) 0.16
x 30000084084
12) 70
x 1.2041007048
+
3)
1
0.0048 x 32
690044635
1
1
1
2
0
0
1
0
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Evaluate The PowerAn exponent tells how many
times a number is multiplied by itself.
34
BaseExponent
3 is written as 3 • 3 • 3 • 3 = 81 4
This exponent is read three to the fourth power.
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Evaluate The PowerEvaluate (0.2)2
4
This means (0.2)(0.2) 0.2
x 0.2
The decimal goes moves two places to the left
00
0. 04
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Calculate Area With Decimals
4 in.
0.58 in.
Area = base x height
Multiply 4 x 0.58
2
0.58
x 4
The decimal moves two places to the left.
3
32
2.32 in2
2
Area is square
units!
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THE END!!!Take out your study guide
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Multiply 0.4 x 0.14
6
Step 1: Write the problem vertically 0.14
x 0.4Step 2: Ignore the decimal points and multiply
Step 3: Determine where the decimal point goes in the product.
The decimal moves 3 places to the left.
1
50
0.056
Multiplying Decimals#5
0
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Evaluate The PowerEvaluate (0.5)2
5
This means (0.5)(0.5) 0.5
x 0.5The decimal moves two
places to the left.
20
0. 25
#6
2
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2 in.
0.98 in Area = base x height
# 7
Multiply 2 x 0.98
6
0.98x 2
The decimal moves two places to the left.
1
91
1.96 in2
1
Area is square
units!
The Area (A) is the number of square units needed to cover a figure.