addition and subtraction

To add or subtract decimals, line up the decimal points and then follow the rules for adding or subtracting whole numbers, placing the decimal point in the same column as above.

When one number has more decimal places than another, use zeros to give them the same number of decimal places.

Examples:

134.56 + 3.7 + 1.212 = 139.472

134.56

+  3.7

    1.212

_______

139.472

 

153 - 1.27 = 151.73

153.00

-   1.27

________

 151.73

 

 

Exercise: calculate:

a) 3.24 + 55.678 + 8.2345 =

b) 333- 6.78 =

c) 1567.65 + 888.8 - 1.2345 =

 

 

 

Solutions: a) 67.1525; b) 326.22; c) 2455.2155