Class 7 - Addition and Subtraction of Decimals: Worksheet

Addition and subtraction of decimals are fundamental arithmetic operations that form the basis of many mathematical and real-world applications. Addition and subtraction of decimals are widely used in contexts such as financial calculations, measurements, data interpretations, etc. Understanding how to properly align decimal points and maintain place value is crucial for error-free calculation of addition and subtraction of decimals. By following systematic methods and practising regularly, learners can develop confidence and efficiency in performing decimal operations. This guide presents step-by-step explanations, examples, and useful strategies to help master the addition and subtraction of decimals.

Table of Contents

• What is the addition and subtraction of decimals?
• Section A: Basic Addition of Decimals
• Section B: Basic Subtraction of Decimals
• Section C: Addition and Subtraction of Unlike Decimals (Different Lengths)
• Section D: Mixed Operations
• Section E: Word Problems on Addition and Subtraction of Decimals?
• Section F: Fill in the Blanks on Addition and Subtraction of Decimals?
• Answer Key

What is the addition and subtraction of decimals?

The addition of decimals means finding the total (sum) of two or more decimal numbers, while the subtraction of decimals means finding the difference between them. The key principle in both operations is to correctly align the  place values. It is necessary to convert numbers to equivalent forms by adding zeros to ensure that each number has the same number of decimal places before performing the operations. 

Key concepts to remember: 

Before performing the operations, remember:

• Align decimal points vertically

• Add zeros if needed to make decimals equal

• Perform operations like whole numbers

• Bring the decimal point straight down
  
  

Section A: Basic Addition of Decimals

Find the sum:

1. 3.5 + 2.4 = ______

2. 6.25 + 1.75 = ______

3. 0.8 + 0.35 = ______

4. 0.52 + 0.315 = ____

5. 12.4 + 3.6 = ______

6. 5.55 + 2.45 = ______

7. 0.5 + 0.35 = ___
   
   

Section B: Basic Subtraction of Decimals

Find the difference:

1. 9.5 − 4.2 = ______

2. 7.25 − 2.15 = ______

3. 5.8 − 1.3 = ______

4. 10.0 − 3.75 = ______

5. 6.4 − 2.6 = ______

6. 2.7 − 0.1 = ______

7. 2 − 0.25 = ______
   
   

Section C: Addition and Subtraction of Unlike Decimals (Different Lengths)

Solve the following: 

1. 3.5 + 2.75 = ______

2. 6.241 − 1.85 = ______

3. 12.45 + 0.6 = ______

4. 9 − 2.37 = ______

5. 7.8 + 3.456 = ______

6. 98.8 - 7.2 = ______

7. 14 - 9.736 = ______
   
   

Section D: Mixed Operations

Solve:

1. 5.5 + 2.3 − 1.2 = ______

2. 10 − 3.75 + 1.25 = ______

3. 6.4 − 2.1 + 3.6 = ______

4. 8.75 + 1.25 − 4.5 = ______

5. 12.5 − 5.25 + 2.75 = ______

6. 17.245 - 3.2 + 7 =  ______

7. 97.22 + 14.1 - 8.888 =  ______
   
   

Section E: Word Problems on Addition and Subtraction of Decimals

1. A notebook costs ₹23.75 and a pen costs ₹12.50. What is the total cost?

2. A rope is 15.5 m long. 7.25 m of rope is cut. What is the length of remaining rope?

3. A student scored 45.75 marks in one test and 32.5 in another. What is the total score?

4. A bottle contains 10 liters of water. 3.75 liters of water are used. How much water is left?

5. The sum of three decimals are 938.629. Two of them are 456.54 and 392.69. Find the third one.

6. Roshni had ₹178.50 with her. She has spent ₹ 138.85. How much money does she have now?

7. Akash bought 15 kg foodgrains. Out of this, 6 kg 200 g is rice, 5 kg 25 kg is wheat and rest is pulses. What is the weight of pulses?

8. Sandra bought biscuits for ₹ 51.25. She gave a ₹100 note to the shopkeeper. How much dis she get back from the shopkeeper?

 

Section F: Fill in the on Blanks Addition and Subtraction of Decimals?

Fill in the blanks :

1. 5.6 + ___ = 9.2

2. ___ − 3.4 = 6.6

3. 7.25 + ___ = 10

4. ___ − 2.75 = 5.25

5. 24.375 + 3.625 + 0.005 = ______

6. 100 − 45.75 − 12.25 = ______

7. 9.999 + 0.001 = ______

8. 50 − 19.99 = ______

 

Answer Key 

Section A:

1. 5.9

2. 8.00

3. 1.15

4. 0.835

5. 16.0

6. 8.00

7. 0.85

Section B

1.  5.3

2. 5.10

3.  4.5

4.  6.25

5.  3.8

6. 2.6

7. 1.75

Section C

1. 6.25

2. 4.35

3. 13.05

4. 6.63

5. 11.256

6. 91.6

7. 4.264

 Section D

1. 6.6

2. 7.5

3. 7.9

4. 5.5

5. 10.0

6. 21.045

7. 102.432

Section E

1. ₹36.25

2. 8.25 m

3. 78.25

4. 6.25 L

5. 89.399

6.  ₹ 39.65

7. 3 kg 55 g pulses

8.  ₹ 48.75

Section F

1. 3.6

2. 10

3. 2.75

4.  8

5.  28.005

6.  42

7.  10

8. 30.01