Show:
Decimal Rules
Adding Decimals
Subtracting Decimals
Multiplication of Decimals
Multiplication
or Division by 10
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

4.2 ÷ 10 =

0.42

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

.56 × 10 =

5.6

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

35.7 ÷ 10

3.57

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

0.08 × 10 =

0.8

500

How do you divide decimals by 10?

Move the decimal point one place to the left.

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

123.45 ÷ 10  

12.345