- Addition of decimals
To add two or more decimals, arrange the numbers in such a way that the decimal
points of the numbers are in the same column and the digits of the same place value
are in the same column. Then add the numbers and put the decimal point directly
under the decimal points of the numbers.
Eg. : Add : 14.5764 + 2.321 + 104.82
014.5764
002.3210
104.8200
121.7194
If unlike decimals are given, convert them into like decimals and then to be added.
When the child is comfortable with normal addition, decimal addition can be performed
by him/her with ease. The only area which needs adequate attention is the placing of
the decimals in the same column. The child must clearly be explained that, once the
decimal point is taken care of then the process is relatively simpler. The teaching of
this concept through abacus will facilitate better understanding. (Refer the section
on abacus to know how decimal addition is performed).
- Subtraction of decimals
To subtract the decimals, arrange the decimals in such a way that the decimal points
are in the same column and the digits having the same place value are in the same
column. Then subtract them and put the decimal directly under the decimal points of
the numbers. If unlike decimals are given, convert them into like decimals and then
subtraction has to be carried out.
Eg. : Subtract : 156.4734 – 121.1432
156.4734
121.1432
35.3302
The process of subtraction of decimals is also similar to normal subtraction, the only
difference being the arrangement of the decimal points in the same column.
