1. 65.1
50.34
DECIMALS
1,234,567

2. Adding, subtracting, Multiplying & Dividing Decimals.
Example
Subtract from 12.1
Solution
N.B. For adding and subtracting decimals keep the decimal points lined up -
3.0025
9.0975

3. Example
Multiply 576 by 23
Solution
576 x 23
1728
11520
13248

4. 12.36 Example Multiply 12.36 from 4 Solution ( 2 d.p.) x 4 ( 0 d.p.)
49.44
( 2 d.p.)
NB When multiplying decimal numbers. Ignore the decimal point until the very end i.e has 2 d.p. 4 has 0 d.p.
Therefore Answer will have (2 + 0) = 2 dec places

5. 2.31 Example Multiply 2.31 by 0.7 Solution ( 2 d.p.) Total 3 d.p. x
1.617
( 3 d.p.)

6. 25.6 120.32 Example Multiply 25.6 by 4.7 Solution ( 1 d.p.) 2 d.p. x
1792
1024
120.32
( 2 d.p.)

7. 3. 3 8 1 5 Example (dividing by a whole no.) Divide 27.052 by 8
Solution 3. 3 8 1 5 8

8. Example (dividing by a decimal) Divide 34.86 by 0.7
Solution
Write ÷ 0.7 as a fraction:
NB The method here is to make the 0.7 into a whole number – remembering that what we do to the bottom no. we must do to the top so they are equivalent.
x10
34.86
0.7
348.6 7
x10
Now we have a whole no.

9. Divide by 0.7
Solution contd. 4 9. 8 8
348.6
ANS: 49.8

10. 90 ANS: 90 Example (dividing by a decimal) Divide 3.6 by 0.04 Solution
360 4
x100
Now we have a whole no. 90
ANS: 90 4
360

11. Working with powers of 10
Examples
Eg (exempli gratia)
2.56 x 10 = 25.6
2.56 x 1000 = 2560
31.8 ÷ 10 = 3.18
5.56 ÷ 1000 =

12. Further Examples
Eg (exempli gratia)
2.89 x 20 = 28.9 = 57.8
x 300 = x 3 =
45 ÷ 40 = 4.5 ÷ 4 = 1.125
31.92 ÷ 3000 = ÷ 3 =