Addition of Fractions (Grade 4)
Addition of fractions means combining two or more fractional parts. In Class 4, you will learn to add like fractions (same denominator) and get an introduction to adding unlike fractions (different denominators).
Adding like fractions is simple: keep the denominator the same and add the numerators.
What is Addition of Fractions - Class 4 Maths (Fractions)?
Adding Like Fractions: When two fractions have the same denominator, add the numerators and keep the denominator unchanged.
a/c + b/c = (a + b)/c
Adding Unlike Fractions: When denominators are different, first find the LCM, convert to like fractions, then add.
Solved Examples
Example 1: Example 1: Add Like Fractions
Problem: Add 2/7 + 3/7.
Solution:
Step 1: Both fractions have denominator 7.
Step 2: Add numerators: 2 + 3 = 5.
Step 3: Keep denominator: 5/7.
Answer: 2/7 + 3/7 = 5/7
Example 2: Example 2: Add Like Fractions (Simplify)
Problem: Add 3/8 + 5/8.
Solution:
Step 1: Add numerators: 3 + 5 = 8.
Step 2: Result: 8/8 = 1.
Answer: 3/8 + 5/8 = 1
Example 3: Example 3: Sum Greater Than 1
Problem: Add 5/6 + 4/6.
Solution:
Step 1: Add numerators: 5 + 4 = 9.
Step 2: Result: 9/6. This is an improper fraction.
Step 3: Convert: 9/6 = 1 3/6 = 1 1/2.
Answer: 5/6 + 4/6 = 1 1/2
Example 4: Example 4: Add Unlike Fractions
Problem: Add 1/3 + 1/4.
Solution:
Step 1: LCM of 3 and 4 = 12.
Step 2: Convert: 1/3 = 4/12, 1/4 = 3/12.
Step 3: Add: 4/12 + 3/12 = 7/12.
Answer: 1/3 + 1/4 = 7/12
Example 5: Example 5: Add Unlike Fractions
Problem: Add 2/5 + 1/3.
Solution:
Step 1: LCM of 5 and 3 = 15.
Step 2: Convert: 2/5 = 6/15, 1/3 = 5/15.
Step 3: Add: 6/15 + 5/15 = 11/15.
Answer: 2/5 + 1/3 = 11/15
Example 6: Example 6: Add and Simplify
Problem: Add 3/10 + 1/10 + 4/10.
Solution:
Step 1: All have denominator 10.
Step 2: Add numerators: 3 + 1 + 4 = 8.
Step 3: Result: 8/10. Simplify: HCF = 2, so 8÷2 / 10÷2 = 4/5.
Answer: 3/10 + 1/10 + 4/10 = 4/5
Example 7: Example 7: Word Problem
Problem: Ria drank 2/5 of a bottle of water in the morning and 1/5 in the afternoon. How much water did she drink in total?
Solution:
Step 1: Both fractions have denominator 5.
Step 2: Add: 2/5 + 1/5 = 3/5.
Answer: Ria drank 3/5 of the bottle.
Example 8: Example 8: Word Problem (Unlike Fractions)
Problem: Aman walked 1/4 km to school and 1/3 km to the library after school. What is the total distance he walked?
Solution:
Step 1: LCM of 4 and 3 = 12.
Step 2: 1/4 = 3/12, 1/3 = 4/12.
Step 3: Total = 3/12 + 4/12 = 7/12 km.
Answer: Aman walked 7/12 km in total.
Example 9: Example 9: Add a Whole Number and a Fraction
Problem: Add 2 + 3/4.
Solution:
Step 1: Write 2 as 2/1. But it is simpler to write 2 as 8/4 (since denominator is 4).
Step 2: Add: 8/4 + 3/4 = 11/4.
Step 3: Convert to mixed number: 11/4 = 2 3/4.
Answer: 2 + 3/4 = 2 3/4
Key Points to Remember
- For like fractions: add numerators, keep the denominator same.
- For unlike fractions: find LCM, convert to like fractions, then add.
- If the sum is an improper fraction, convert it to a mixed number.
- Always simplify the answer if possible.
- To add a whole number and a fraction, convert the whole number to a fraction with the same denominator.
- The denominator tells you the size of the parts; only parts of the same size can be added directly.
Practice Problems
- Add 4/9 + 2/9.
- Add 5/12 + 7/12. Simplify your answer.
- Add 1/6 + 1/4.
- Add 2/3 + 1/5.
- Priya read 3/8 of a book on Monday and 2/8 on Tuesday. What fraction has she read so far?
- Add 3 + 2/5. Write as a mixed number.
- Neha drank 1/3 litre of juice and Meera drank 1/4 litre. How much juice did they drink together?
Frequently Asked Questions
Q1. How do you add fractions with the same denominator?
Add the numerators and keep the denominator unchanged. For example, 2/5 + 1/5 = 3/5.
Q2. How do you add fractions with different denominators?
Find the LCM of the denominators, convert both fractions to equivalent fractions with that LCM as the denominator, and then add the numerators.
Q3. Why can you not just add the denominators?
The denominator tells you the size of each part. Adding denominators would change the size of the parts, giving an incorrect answer. Only numerators (the count of parts) are added.
Q4. What if the answer is an improper fraction?
Convert it to a mixed number. Divide the numerator by the denominator. The quotient is the whole part and the remainder is the new numerator. For example, 9/4 = 2 1/4.
Q5. Do you always need to simplify after adding?
It is good practice to always simplify. Check if the numerator and denominator of the answer share a common factor and divide both by it.
Q6. Can you add more than two fractions?
Yes. If all are like fractions, add all the numerators. If they are unlike, find the LCM of all denominators, convert all to like fractions, and then add.
Q7. How do you add a whole number to a fraction?
Write the whole number as a fraction with the same denominator. For example, 3 + 1/4: write 3 as 12/4, then 12/4 + 1/4 = 13/4 = 3 1/4.
Q8. What is the sum of 0 and any fraction?
Adding 0 to any fraction gives the same fraction. For example, 0 + 3/5 = 3/5.
Q9. Is addition of fractions in the NCERT Class 4 syllabus?
Yes. Class 4 covers addition of like fractions in detail and introduces addition of unlike fractions. Students also learn to simplify answers and convert improper fractions to mixed numbers.
Related Topics
- Subtraction of Fractions (Grade 4)
- Fractions (Grade 4)
- Equivalent Fractions (Grade 4)
- Simplifying Fractions
- Comparing Fractions (Grade 4)
- Ordering Fractions
- Mixed Numbers and Improper Fractions
- Fraction Word Problems (Grade 4)
- Fractions on a Number Line (Grade 4)
- Proper and Improper Fractions
- Fraction of a Number (Grade 4)
