Class 8 Maths – Chapter 16: Playing with Numbers
Step 5: Tests of Divisibility
Divisibility tests help us check whether a number is divisible by another number without actual division.
🔹 Divisibility Rules
- Divisible by 2: Last digit is even (0, 2, 4, 6, 8)
- Divisible by 3: Sum of digits is divisible by 3
- Divisible by 4: Last two digits divisible by 4
- Divisible by 5: Last digit is 0 or 5
- Divisible by 6: Divisible by both 2 and 3
- Divisible by 9: Sum of digits divisible by 9
- Divisible by 10: Last digit is 0
📘 Solved Examples
- Is 345 divisible by 5? → Yes (last digit 5)
- Is 729 divisible by 9? → 7+2+9=18 → Yes
- Is 132 divisible by 6? → Even & sum=6 → Yes
📝 Exam Tips
- Write the rule first
- Show digit sum clearly
- Conclude with “Hence proved”
🧠 Easy Memory Trick:
2 → Even
3 → Digit Sum
9 → Big Digit Sum
📘 Class 8 Mathematics – Complete Library
CBSE | NCERT | State Syllabus
Chapter 1: Rational Numbers
Chapter 2: Linear Equations in One Variable
Chapter 3: Understanding Quadrilaterals
Chapter 4: Practical Geometry
Chapter 5: Data Handling
Chapter 6: Squares and Square Roots
Chapter 7: Cubes and Cube Roots
- NCERT Notes
- MCQs
- Worksheet
- Worksheet Answers
- Mind Map & Easy Tricks
- Important Exam Questions
- Very Important Questions
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