📚 Class 2 Mathematics – Chapter 3: Subtraction
🔹 1. Introduction
Subtraction is the process of taking away one number from another.
The symbol for subtraction is “−”.
The result of subtraction is called the difference.
💡 Example:
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8 − 3 = 5
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Here, 8 is the minuend, 3 is the subtrahend, and 5 is the difference.
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🔹 2. Subtraction of Small Numbers (Within 20)
Start with small numbers, then gradually move to larger numbers.
Example:
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9 − 4 = ?
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Count 4 backward from 9 → 8, 7, 6, 5
✅ Answer: 5
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🔹 3. Subtraction Using Number Line
A number line helps in visualizing subtraction.
Example: 12 − 5 = ?
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Start at 12 on the number line.
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Move 5 steps backward → 11, 10, 9, 8, 7
✅ Answer: 7
🔹 4. Subtraction of Tens and Ones (Two-digit Numbers)
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Subtract ones first, then tens.
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If the top digit is smaller than the bottom digit in ones, borrow 1 from tens.
Example: 34 − 18
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Ones: 4 − 8 → borrow 1 from tens
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Tens: 3 − 1 (after borrowing, 2 left)
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Ones after borrowing: 14 − 8 = 6
✅ Answer: 16
🔹 5. Borrowing in Subtraction
Step 1: Check if top digit in ones place is smaller than bottom.
Step 2: Borrow 1 from tens place.
Step 3: Subtract ones, then tens.
Example: 52 − 27
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Ones: 2 − 7 → borrow 1 from tens (5 becomes 4)
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Ones: 12 − 7 = 5
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Tens: 4 − 2 = 2
✅ Answer: 25
🔹 6. Subtraction of Three Numbers
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Subtract first two numbers, then subtract the third.
Example: 20 − 5 − 3
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Step 1: 20 − 5 = 15
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Step 2: 15 − 3 = 12
✅ Answer: 12
🔹 7. Properties of Subtraction
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Non-commutative: Changing the order changes the difference
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8 − 3 ≠ 3 − 8
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Non-associative: Grouping numbers differently changes the result
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(20 − 5) − 3 ≠ 20 − (5 − 3)
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💡 Tip: Always subtract in the correct order!
🔹 8. Word Problems (Simple Subtraction)
1️⃣ Ram had 12 apples. He gave 5 apples to his friend. How many apples does he have now?
✅ Answer: 12 − 5 = 7 apples
2️⃣ There are 20 birds on a tree. 8 birds flew away. How many birds are left?
✅ Answer: 20 − 8 = 12 birds
🔹 9. Practice Questions
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15 − 6 = ?
✅ Answer: 9 -
34 − 17 = ?
✅ Answer: 17 -
20 − 5 − 3 = ?
✅ Answer: 12 -
Subtract 52 − 28 using borrowing method.
✅ Answer: 24 -
A shop had 45 pencils. 18 pencils were sold. How many pencils are left?
✅ Answer: 45 − 18 = 27
🔹 10. Summary
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Subtraction = taking away numbers to get a difference
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Symbols: − → “minus”
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Properties: Non-commutative, Non-associative
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Methods: Using number line, borrowing method, subtracting three or more numbers
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Word Problems: Apply subtraction in real-life situations