Decimal Rule
Addition of Decimals
Subtraction of Decimals
Dividing Fractions
Reciprocals
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

2 divided by 4/7

14/4

100

What is the recriprocal of 4/5

5/4

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

2 divided by 4/7

5/81

200

What is the recriprocal of 676/25 and 1256/9

25/676

9/1256

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

7 divided by 6 1/2

14/13

300

What is the recriprocal of 5

1/5

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

6/15 divided by 5/6

36/75

400

What is the recriprocal of 7/8

8/7

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
8.07 + .0976 + 23.3 + 48 =
79.4676
500
5.45 - 3.799 =
1.651
500

4⁄5 divided by 5 1/2

8/55

500

What is the recriprocal of 50/3

3/50

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