Decimal Rule
Addition of Decimals
Subtraction of Decimals
Multiplication of Decimals
Division of Decimals
100
How do you add decimals?
You line up the decimals and then add the numbers.
100
58.9 + 3.04 =
61.94
100
3.95 - 2.7 =
1.25
100
.6 x 2.1 =
1.26
100

64.2 divided by 5

12.84

200
How do you subtract decimals?
You line up the decimals and then subtract the numbers.
200
.004 + 5.1 =
5.104
200
95.29 - 1.3 =
93.99
200
4.25 x 21 =
89.25
200

5.43 divided by 15

0.362

300
What do you do if there are not enough digits in the top number to subtract a problem?
You have to add on zero's.
300
.9843 + 2.67 =
3.6543
300
125 - .68 =
124.32
300
.03 x .03 =
.0009
300

Four friends decide to share a pizza that costs $13.16. How much does each person have to pay?

$3.29

400
How do you multiply decimals?
You multiply the numbers and then you count how many spaces there are to the right of the decimals and count them over to the left in the answer.
400
5 + 2.78 + .030 =
7.81
400
.468 - .059 =
.409
400
2.003 x .05 =
.10015
400

456.16 divided by 16

28.51

500

How do you divide decimals?

Bring the decimal straight up and divide normally.

500
8.07 + .0976 + 23.3 + 48 =
79.4676
500
5.45 - 3.799 =
1.651
500
.312 x 1.67 =
.52104
500

152.8 divided by 4

38.2

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