Class 8 Maths – Chapter 16: Playing with Numbers
Step 2: Divisibility Rules
1️⃣ What is Divisibility?
A number is said to be divisible by another number if it can be divided exactly without leaving any remainder.
2️⃣ Divisibility Rule of 2
A number is divisible by 2 if its last digit is even (0, 2, 4, 6, 8).
Example: 246 ✔ (last digit 6)
3️⃣ Divisibility Rule of 3
A number is divisible by 3 if the sum of its digits is divisible by 3.
Example: 123 → 1+2+3=6 ✔
4️⃣ Divisibility Rule of 5
A number is divisible by 5 if its last digit is 0 or 5.
Example: 450 ✔
5️⃣ Divisibility Rule of 9
A number is divisible by 9 if the sum of its digits is divisible by 9.
Example: 729 → 7+2+9=18 ✔
6️⃣ Divisibility Rule of 10
A number is divisible by 10 if its last digit is 0.
Example: 890 ✔
7️⃣ Why Divisibility Rules are Useful?
- Save time in calculations
- Helpful in exams
- Makes mental maths easy
📌 Exam Tips
- Always check last digit first
- Add digits carefully
- Write steps clearly in answers
🧠Easy Memory Trick:
2 → Even | 3 → Digit Sum | 5 → 0 or 5 | 9 → Digit Sum | 10 → 0
📘 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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