Addition and Subtraction of Decimals

Addition and subtraction of decimals are bit complex as compared to performing the operations on natural numbers. Before we learn how to add or subtract any two or more than two given decimals, first let us understand about decimals. The decimal number is used to represent a number with greater precision in comparison to integers or whole numbers. It uses a dot in between numbers, which is said to be a decimal point. Decimals are nothing but the simplified version of fractions. Check problems based on decimal fractions here.

For example, when we have to divide 3 pies among 4 kids, we cannot represent the pies received by each kid in terms of integers alone, as each kid has received pies that lie between 0 and 1. In order to deal with other similar problems, the concept of decimal was introduced. Thus, the concept of addition, multiplication, division and subtraction of decimals is an important topic. Let us say, two friends are contributing to buy cricket ball that costs Rs 20. One of them has Rs 7.50 and the other has Rs 18.50. In order to know, how much money each will have to contribute and how much they will be left with, they must understand the concept of addition and subtraction of decimals.

Also, read:

Addition of Decimals

Addition of decimals is performed using the following steps:

  1. The numbers are first padded with zero depending upon the maximum digits present after the decimal for any of the numbers. For example, while adding 3.456 to 7.1, since the number 3.456 has the number of digits after the decimal, the padding is done according to 3.456. Since 3.456 have 3 digits after the decimal, we pad two zeros after 1. Hence, 7.1 to three places is 7.100.
  2. The numbers are lined up vertically along with each other and then added as shown below:

  7.100

+3.456

———

10.556

———

Let us understand the concept more clearly with the help of the following examples:

Examples of Decimal Addition

Let us see some examples of adding decimals.

Example 1: Addition 1.091 + 1.33.

Addition of Decimals

Example 2: Addition 0.0075 + 5.

Adding two decimals

Example 3: Add 9.1, 3.22, 0.66.

Solution: Given, 9.1, 3.22 and 0.66.

As we can see, 9.1 has only one digit after decimal but 3.22 and 0.66 have two digits.

Hence, we can write 9.1 as 9.10

Now add all the three decimals.

  9.10

+3.22

+0.66

——–

12.98

——

Subtraction of decimals

Subtraction of decimals is performed using the following steps:

  1. The numbers are first padded with zero depending upon the maximum digits present after the decimal for any of the numbers. For example, while subtracting 3.456 from 7.1, since the number 3.456 has more number of digits after the decimal, the padding is done according to 3.456. Since 3.456 have 3 digits after the decimal, we pad 7.1 to three places as 7.100.
  2. The numbers are lined up vertically along with each other, as shown below

Subtraction of decimalsNow, subtract to get the result.

Let us understand the concept more clearly with the help of the following examples:

Example 1: Subtraction: 7.304 – 1.15

Subtraction of decimals example

 

Example 2: Subtraction 4.1 – 0.94

Subtracting Decimals

To learn more about the topic, download BYJU’S – The Learning App from Google Play Store and watch interactive videos. Also, take free tests to practice for exams.

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