Decimals

Addition & Subtraction

Example Find: 15.12 + 3.2 - 12.04

Solution: 15.12 + 3.2 = 15.12 + 3.20 = 18.32

15.12 + 3.2 - 12.04

=18.32 – 12.04 = 6.28

Multiplication

Example

Find: 12.5

x

35.02

Solution (1) First multiply: 125 x 125 x 3502 = 437750 3502 (2) Second find he sum of he decimal places (to the right) of the wo numbers 12.

5 and 35.

02 , which is here one plus two; that is three.

(3) Now write the result of step (1), count three decimal places from the left and place the decimal point at the start of the third figure, like that: 437 .

750

Justification Another way to present the solution

Find

: 12 .

5  35 .

02

Solution

: 12 .

5  35 .

02  125  10 3502 100  125  3502 1000  437750 1000  437 .

750  437 .

75

Division

Examples

Find

: 37 .

5  1 .

25

Solution

: 37 .

5  1 .

25  375 10  125 100  375  10 100 125  3  1 10 1  30 Example (1)

Example (2)

Find

: 0 .

375  1 .

25

Solution

: 0 .

375  1 .

25  375 1000  125 100  375 1000  100 125  3 10  1 1  3 10  0 .

3

Example (3)

Find

: 0 .

0375  12 .

5

Solution

: 0 .

0375  12 .

5  375 10000  125 10  375 10000  10 125  3 1000  1 1  3 1000  0 .

003

Example (4)

Find

: 1500  1 .

2

Solution

: 1500  1 .

2  1500  12 10  1500  10 12   500  10 4  5 ( 25 )( 10 )  1250