CLASS-5
ADDITION OF DECIMAL NUMBER

ADDITION OF DECIMAL NUMBER

The addition of decimal number is needed for measurement of distance, weight and other calculations.

Example 1.)  Add  0.25 + 2.357 + 42.7

Ans.) In the above decimal form, you can observe there is three decimal numbers form like one decimal number, two decimal number and three decimal number.

Step.1)  First convert decimal from non-similar to similar number form which will be higher side as per the place value. So, convert all the decimal number to three decimal numbers.

Step.2) Write the addends one below the other so that the decimal points of all the addends are below the other one.

Step.3) Now, add like as you does always for the whole number (without decimal).                                                             

Step.4) put the decimal point in the sum directly below the Decimal points in the addends

Important Fact About Decimal Addition

a) If does any changes in the order of addend, in spite of that no changes or effect happen in sum of Decimals.

Example. If you wish to add  2.35, 3.45, 4.25 ; then whatever the order of addend is there result will be the same.  

  2.35 + 3.45 + 4.25 = 10      ;    4.25 + 2.35 + 3.45 = 10

  3.45 + 2.35 + 4.25 = 10      ;    4.25 + 3.45 + 2.35 = 10

b) The sum of any Decimal number with zero ‘0’ is the same decimal number as a result of addition.

Example- 4.35 + 0 = 4.35, 3.78 + 0 = 3.78,  7.864 + 0 = 7.864,  0 + 6.89 = 6.89,  0 + 12.48 = 12.48

c) Always assign a unit to the final sum if units are involved in the addends.

Example 2.)  Add   12.4504 + 242.75 + 124.38 + 7.865

 Ans.) In the above decimal form you can observe there  four decimal number form like one decimal number, two decimal numbers, three decimal numbers and four decimal numbers.

Step.1)  First convert decimal from non-similar to similar number form which will be higher side as per the place value. so, convert all the decimal number to four decimal numbers.

Step.2) Write the addends one below the other so that the decimal points of all the addends are one below the other.

Step.3) Now, add like as you do always for the whole number (without decimal).

 Step.4) put the decimal point in the sum directly below the Decimal points in the addends