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Multiplying Decimals
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How to Multiply Decimals
Multiply without the decimal point, and then re-insert the
decimal point in the correct spot!
Here are the rules for multiplying decimal numbers:


Multiply the numbers just as if they were whole numbers:
Starting on the right, multiply each digit in the top number by
each digit in the bottom number, just as with whole numbers.


Add the products.
Then put the decimal point in the answer - it will have as many
decimal places as the two original numbers combined.
Place the decimal point in the answer by starting at the right and
moving the point the number of places equal to the sum of the
decimal places in both numbers multiplied.
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Example: Multiply 0.03 by 1.1
0.03 ×
start with:
1.1
multiply without decimal points:
0.03 has 2 decimal places,
and 1.1 has 1 decimal place,
so the answer has 3 decimal places:
Answer= 0.033
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3 × 11 =
33
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Hint: Use estimating to help you check the
placement of the decimal point. You could
round 37.7 to 40 and 2.8 to 3. It's easy to
multiply 3 x 40 so you know your answer
should be close to 120
Find the product of 9.683 x 6.1=?
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2.
3.
4.
Line up the
numbers on the
right,
multiply each
digit in the top
number by
each digit in the
bottom number (like whole numbers),
add the products,
and mark off decimal places equal to the sum of
the decimal places in the two numbers being
multiplied.
Example: Multiply 0.25 by 0.2
start with:
0.25 × 0.2
multiply without
decimal points:
25 × 2 = 50
0.25 has 2 decimal
places,
and 0.2 has 1 decimal
place,
so the answer
has 3 decimal places: 0.050
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Example: Multiply 102 by 0.22
start with:
102 × 0.22
multiply without decimal points:
102 × 22 = 2,244
102 has 0 decimal places,
and 0.22 has 2 decimal place,
so the answer has 2 decimal places: 22.44
And that's all.
Just remember: the answer should have the same
number of decimal places as are in both the
numbers you are multiplying.
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Dividing Decimals
Quick method: use Long Division without the decimal point,
then re-insert the decimal point in the answer.
Dividing a Decimal Number by a Whole Number
To divide a decimal number by a whole number:

Use Division or Long Division.(divide,multiply,subtract,
divide,bring-down)
Then put the decimal point in the same spot as the dividend
(the number being divided) in other words divide as usual but
keep the decimal points aligned.
When dividing a decimal by a whole number, For example:
5.75 ÷ 5 =
Note that the decimal points are in the same place.
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Example: Divide 9.1 by 7
Use Long Division:
13
7 )9.1
9
7
21
21
0
Put the decimal point in the answer directly above the decimal
point in the dividend:
1.3
7 )9.1
The answer is =
1.3
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