How to Do Decimals in Math

There are many students who are all at sea while solving mathematical sums pertaining to decimals. Such problems ofcourse involve addition, subtraction, multiplication and division of decimals. The main problem that some children face is placing the decimal properly in the calculated value after having done addition, subtraction, multiplication and division. This is because when a two-digit amount is multiplied with another two-digit amount, the answer is in a 3-digit amount. In this case the decimal is to be placed properly which often confuses a lot of students. Hence, there are a few things that must be remembered while solving decimals.


  • 1

    First of all for adding decimals, you should write the number to be added in such a way that the decimal in one figure is exactly under the decimal of the other.

  • 2

    Now once you have placed the decimals in the way shown above, put zeros to the number in denominator so that the number has the same length as that of the numerator.
    + 1.200

  • 3

    After putting zeros in the way as mentioned above, the calculations become easier. Now you can easily add the two amounts placing the decimal accordingly.
    + 1.200

  • 4

    Now the same numbers can be used for subtraction, with the only change being of the subtraction sign and no change in the decimal place.
    - 1.200

  • 5

    Using the same numbers for multiplication, just change the sign from subtraction to multiplication and while multiplying simply ignore the presence of decimals and solve like normal multiplication.
    x 1.200

  • 6

    As you have ignored the decimals so there is no decimal in the product of the two numbers. Now calculate the significant numbers after decimals. There are 3-digits after decimal in the numerator and one significant digit after decimal in the denominator which is 2.

  • 7

    As you will combine the two, it will be four decimal places in total. This means that you will have to place the decimal in “21048” after 4 digits moving from right to left.
    x 1.200
    2.1048                   Moving FOUR digits from RIGHT to LEFT to place the decimal

  • 8

    Now for division, the first thing you should do is get rid of the decimals. For example, removing decimal from 1.752 will make it 1752 and from 1.2 will make it 12 simply.

  • 9

    As you will divide 1752 with 12, the answer will be 146. Now as you will make it into 1.752 and 1.2, the answer will be 1.46. This will be done by the following method:

    1.752/1000 = 1752
    1.2/10 = 12
    1752 / 12 = 146
    146/ 100 = 1.46

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