📚 Class 2 Mathematics – Chapter 1: Numbers
🔹 1. Introduction
Numbers are symbols used to count, measure, and compare things.
In Class 2, students learn numbers up to 100 or more, depending on the curriculum.
Numbers are mainly of two types:
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Natural Numbers – 1, 2, 3, 4…
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Whole Numbers – 0, 1, 2, 3…
💡 Tip:
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Natural numbers start from 1.
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Whole numbers start from 0.
🔹 2. Place Value and Face Value
Every digit in a number has its own value depending on its place.
2.1 Face Value
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The face value of a digit is the digit itself, no matter where it is.
Example:
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Number: 356
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Face value of 5 = 5
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2.2 Place Value
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The place value depends on the position of the digit in the number.
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It is calculated as: Digit × Place
Example:
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Number: 356
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Place value of 5 = 5 × 10 = 50
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Place value of 3 = 3 × 100 = 300
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🔹 3. Expanded Form
A number can be written as the sum of its place values.
Example:
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Number: 356
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Expanded form: 300 + 50 + 6
🔹 4. Comparing Numbers
We can compare numbers using:
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Greater than ( > )
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Less than ( < )
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Equal to ( = )
Example:
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45 > 32
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23 < 56
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78 = 78
🔹 5. Ordering Numbers
Numbers can be arranged in ascending (small to big) or descending (big to small) order.
Example:
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Ascending: 12, 23, 34, 45
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Descending: 45, 34, 23, 12
🔹 6. Even and Odd Numbers
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Even numbers – divisible by 2 (0, 2, 4, 6, 8…)
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Odd numbers – not divisible by 2 (1, 3, 5, 7, 9…)
💡 Tip: Last digit decides:
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0,2,4,6,8 → Even
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1,3,5,7,9 → Odd
🔹 7. Successor and Predecessor
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Successor – the number that comes after a given number
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Predecessor – the number that comes before a given number
Example:
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Number: 45
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Successor = 46
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Predecessor = 44
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🔹 8. Number Patterns
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Numbers can form patterns based on counting by 1, 2, 5, 10, etc.
Example:
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Counting by 1: 1, 2, 3, 4…
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Counting by 2: 2, 4, 6, 8…
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Counting by 5: 5, 10, 15, 20…
💡 Tip: Patterns help in quick calculation and understanding number sequences.
🔹 9. Practice Questions
1️⃣ Write the place value of 7 in 372.
✅ Answer: 7 × 10 = 70
2️⃣ Write the successor and predecessor of 89.
✅ Answer: Successor = 90, Predecessor = 88
3️⃣ Arrange in ascending order: 45, 12, 67, 34
✅ Answer: 12, 34, 45, 67
4️⃣ Identify even and odd numbers: 23, 34, 45, 56
✅ Answer: Even: 34, 56; Odd: 23, 45
5️⃣ Write 456 in expanded form.
✅ Answer: 400 + 50 + 6
🔹 10. Summary
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Numbers – used to count, measure, and compare.
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Place Value – depends on the position of digit.
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Face Value – the digit itself.
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Even & Odd Numbers – based on divisibility by 2.
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Successor & Predecessor – numbers before and after.
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Ordering & Patterns – arranging numbers and identifying sequences.