CLASS-4
ADDITION OF DECIMAL

ADDITION OF DECIMAL NUMBER -

As we are well aware about the addition of digits, similarly we will learn about addition.

There are some simplified example of addition of decimal fraction is given below for your better understanding -

                                                  3          9

Example.1) Add following decimal fraction  ------ + ------

                                                                        10        10

            3          9         3 + 9          12

Ans.)   ------ + ------ = --------- = -------

           10         10          10            10 

         =>       0.3  +  0.9   =   1.2

so, required result of addition is 1.2    (Ans.)

                                                                   34           63

Example.2)  Add following decimal fraction  -------- + --------

                                                   100          100

            34          63         34 + 63         97

Ans.)   ------- + ------- = ---------- = -------

           100         100          100           100

   =>    0.34  +  0.63  =  0.97

so, required result of addition is 0.97.      (Ans.)   

Principal/Properties Of Decimals -

a) The sum of a decimal number and zero is the same decimal number. Example: 4.06 + 0 = 4.06

b) Change of order of decimal numbers does not change their sum. Example: 4.29 + 15.8 = 15.8 + 4.29

There are some steps for Addition of Decimal Numbers -

Step.1)  Write the numerals in column form one below the other.

Step.2)  All the decimal points should be in the same column.

Step.3)  Convert into like decimals by adding zeroes.

Step.4)  Start adding from the thousandths place.

Step.5)  If there are any carry numbers in any place, it will be carried to the previous column.

Example.1) Find the result of addition of decimal numbers 8.574, 74.48, 57.92 

Ans.) 

Step.1) Write the numerals in column form one below the other.

Step.2) All the decimal points should be in the same column.

Step.3) Highest decimal places is 3. So, we have to convert into like decimals by adding zeroes (0).

Step.4) We have to start add the digit of given decimal number from 'Thousandths' column, if there is any carry number then it will be carried to the 'Hundredths' column, and if there is any carry number then it will be carried to the 'Tenths' column. The process should be continued till last column of decimal places.

So, required result is 140.974         (Ans.)

Example.2) Find the result of addition of decimal numbers 16.41, 104.7, 125.322 

Ans.) 

Step.1) Write the numerals in column form one below the other.

Step.2) All the decimal points should be in the same column.

Step.3) Highest decimal places is 3. So, we have to convert into like decimals by adding zeroes (0).

Step.4) We have to start add the digit of given decimal number from 'Thousandths' column, if there is any carry number then it will be carried to the 'Hundredths' column, and if there is any carry number then it will be carried to the 'Tenths' column. The process should be continued till last column of decimal places.

so, the required result is 246.432          (Ans.)

Example.3) Find the result of addition of decimal numbers 96.787, 204.56, 85.3 

Ans.) 

Step.1) Write the numerals in column form one below the other.

Step.2) All the decimal points should be in the same column.

Step.3) Highest decimal places is 3. So, we have to convert into like decimals by adding zeroes (0).

Step.4) We have to start add the digit of given decimal number from 'Thousandths' column, if there is any carry number then it will be carried to the 'Hundredths' column, and if there is any carry number then it will be carried to the 'Tenths' column. The process should be continued till last column of decimal places.

So, the required result is 386.647         (Ans.)

Example.4) Find the result of addition of decimal numbers 96.728, 4.54, 170.309 

Ans.) 

Step.1) Write the numerals in column form one below the other.

Step.2) All the decimal points should be in the same column.

Step.3) Highest decimal places is 3. So, we have to convert into like decimals by adding zeroes (0).

Step.4) We have to start add the digit of given decimal number from 'Thousandths' column, if there is any carry number then it will be carried to the 'Hundredths' column, and if there is any carry number then it will be carried to the 'Tenths' column. The process should be continued till last column of decimal places.

So, the required result is 271.577        (Ans.)