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

8.6 + 3.3 =

11.9

100

3.95 - 2.71 =

1.24

100

5.2 x 6 =

31.2

100

4.5 divided by 5

0.9

200
How do you subtract decimals?
You line up the decimals and then subtract the numbers.
200

54.4 + 5.123 =

58.523

200

95.2 - 1.12 =

94.08

200

3.7 x 9 =

33.3

200

3.82 divided by 2  =

1.91

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

1.843 + 67 =

68.843

300

25.2 - 3.12 =

22.08

300

17.3 x 4.5 =

77.85

300

36.25 divided by 5 =

7.25

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

85.1 + 7.038 =

92.138

400

85.4 - 3.12 =

82.28

400

2.03 x 0.05 =

0.1015

400

203.16 divided by 0.4 =

507.9

500
How do you divide decimals?
You have to get rid of the decimals on the outside by moving the decimals on the inside. Then bring the decimal straight up and divide normally.
500

23.389 + 48 =

71.389

500

54 - 7.04 =

46.96

500

0.03 x 0.03

0.0009

500

184.05 divided by 0.02

9202.5

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