Subtraction of Fractions (Grade 4)
Subtraction of fractions means finding the difference between two fractional parts. In Class 4, you will learn to subtract like fractions (same denominator) and unlike fractions (different denominators).
Subtracting like fractions is straightforward: keep the denominator and subtract the numerators.
What is Subtraction of Fractions - Class 4 Maths (Fractions)?
Subtracting Like Fractions: When two fractions have the same denominator, subtract the numerators and keep the denominator unchanged.
a/c − b/c = (a − b)/c
Subtracting Unlike Fractions: When denominators are different, find the LCM, convert to like fractions, then subtract.
Solved Examples
Example 1: Example 1: Subtract Like Fractions
Problem: Subtract 5/8 − 2/8.
Solution:
Step 1: Both have denominator 8.
Step 2: Subtract numerators: 5 − 2 = 3.
Answer: 5/8 − 2/8 = 3/8
Example 2: Example 2: Subtract Like Fractions (Simplify)
Problem: Subtract 7/10 − 3/10.
Solution:
Step 1: Subtract numerators: 7 − 3 = 4.
Step 2: Result: 4/10. Simplify: HCF(4,10) = 2. So 4÷2 / 10÷2 = 2/5.
Answer: 7/10 − 3/10 = 2/5
Example 3: Example 3: Subtract Unlike Fractions
Problem: Subtract 3/4 − 1/3.
Solution:
Step 1: LCM of 4 and 3 = 12.
Step 2: Convert: 3/4 = 9/12, 1/3 = 4/12.
Step 3: Subtract: 9/12 − 4/12 = 5/12.
Answer: 3/4 − 1/3 = 5/12
Example 4: Example 4: Subtract Unlike Fractions
Problem: Subtract 5/6 − 1/4.
Solution:
Step 1: LCM of 6 and 4 = 12.
Step 2: Convert: 5/6 = 10/12, 1/4 = 3/12.
Step 3: Subtract: 10/12 − 3/12 = 7/12.
Answer: 5/6 − 1/4 = 7/12
Example 5: Example 5: Subtract from 1
Problem: Subtract 1 − 3/5.
Solution:
Step 1: Write 1 as 5/5.
Step 2: Subtract: 5/5 − 3/5 = 2/5.
Answer: 1 − 3/5 = 2/5
Example 6: Example 6: Subtract and Simplify
Problem: Subtract 9/12 − 3/12.
Solution:
Step 1: Subtract numerators: 9 − 3 = 6.
Step 2: Result: 6/12. Simplify: HCF = 6. So 6÷6 / 12÷6 = 1/2.
Answer: 9/12 − 3/12 = 1/2
Example 7: Example 7: Word Problem
Problem: Arjun had 7/8 of a pizza. He ate 3/8. What fraction is left?
Solution:
Step 1: Both have denominator 8.
Step 2: Subtract: 7/8 − 3/8 = 4/8.
Step 3: Simplify: 4/8 = 1/2.
Answer: 1/2 of the pizza is left.
Example 8: Example 8: Word Problem (Unlike Fractions)
Problem: Meera had 3/4 metre of ribbon. She used 1/3 metre. How much ribbon is left?
Solution:
Step 1: LCM of 4 and 3 = 12.
Step 2: 3/4 = 9/12, 1/3 = 4/12.
Step 3: Subtract: 9/12 − 4/12 = 5/12.
Answer: Meera has 5/12 metre of ribbon left.
Example 9: Example 9: Subtract a Fraction from a Whole Number
Problem: Subtract 3 − 2/3.
Solution:
Step 1: Write 3 as 9/3.
Step 2: Subtract: 9/3 − 2/3 = 7/3.
Step 3: Convert: 7/3 = 2 1/3.
Answer: 3 − 2/3 = 2 1/3
Key Points to Remember
- For like fractions: subtract numerators, keep the denominator same.
- For unlike fractions: find LCM, convert to like fractions, then subtract.
- Always simplify the answer to its lowest terms.
- To subtract a fraction from 1, write 1 as a fraction with the same denominator.
- To subtract from a whole number, convert the whole number to an improper fraction.
- The result of subtraction should never be negative at this level (always subtract the smaller from the larger).
Practice Problems
- Subtract 6/9 − 2/9.
- Subtract 11/12 − 5/12. Simplify your answer.
- Subtract 2/3 − 1/4.
- Subtract 1 − 5/7.
- Dev had 4/5 of a chocolate bar. He gave 1/5 to his friend. How much does he have left?
- Subtract 5 − 3/4. Write as a mixed number.
- Aditi had 5/6 litre of juice. She drank 1/3 litre. How much is left?
Frequently Asked Questions
Q1. How do you subtract fractions with the same denominator?
Subtract the numerators and keep the denominator the same. For example, 7/9 - 4/9 = 3/9 = 1/3.
Q2. How do you subtract fractions with different denominators?
Find the LCM of the denominators, convert both to like fractions, then subtract the numerators. For example, 3/4 - 1/6: LCM = 12, so 9/12 - 2/12 = 7/12.
Q3. Can the answer be zero?
Yes. If the numerators are equal in like fractions, the result is 0. For example, 5/8 - 5/8 = 0.
Q4. How do you subtract a fraction from 1?
Write 1 as a fraction with the same denominator. For example, 1 - 2/7: write 1 as 7/7, then 7/7 - 2/7 = 5/7.
Q5. Can you subtract a larger fraction from a smaller one?
In Class 4, we always subtract the smaller fraction from the larger one, so the answer is not negative. Negative fractions are covered in higher classes.
Q6. Should you simplify after subtracting?
Yes. Always check if the answer can be simplified. Divide the numerator and denominator by their HCF to get the simplest form.
Q7. How is subtraction of fractions used in daily life?
When you use part of something and want to know what is left. For example, if you have 3/4 of a cake and eat 1/4, you have 2/4 = 1/2 left.
Q8. What is the difference between adding and subtracting fractions?
Both require like denominators. In addition, you add the numerators. In subtraction, you subtract the numerators. The denominator stays the same in both.
Q9. Is subtraction of fractions in the NCERT Class 4 syllabus?
Yes. Class 4 covers subtraction of like fractions and introduces subtraction of unlike fractions. Students learn to simplify and convert improper fractions to mixed numbers.
Related Topics
- Addition 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)
