Bank Exam Speed Maths Master Series Page 15 | Number System Tricks & Fast Calculation Methods

 

 Bank Exam Speed Maths Master Series – Page 15

Number System Tricks & Fast Calculation Methods

Shaktimatha Learning – Speed Maths Academy
Learn Number System shortcut tricks, aptitude formulas, and fast calculation methods for Bank Exams, SSC, Railways, Insurance, and Competitive Exams.

 Importance of Number System in Competitive Exams

Number System is one of the most important foundation topics in:

• Bank Exams
• SSC
• Railway Exams
• Insurance Exams
• Quantitative Aptitude

This topic is highly useful in:

• Simplification
• Arithmetic calculations
• Divisibility problems
• Remainder problems
• Data Interpretation

🎯 What is Number System?

Number System is the study of:

• Natural numbers
• Whole numbers
• Integers
• Rational numbers
• Prime numbers
• Factors & multiples

 Types of Numbers

Type	Example
Natural Numbers	1,2,3...
Whole Numbers	0,1,2,3...
Integers	-3,-2,-1,0,1
Even Numbers	2,4,6,8
Odd Numbers	1,3,5,7
Prime Numbers	2,3,5,7

 Divisibility Rules

Number	Rule
2	Last digit even
3	Sum of digits divisible by 3
4	Last 2 digits divisible by 4
5	Last digit 0 or 5
6	Divisible by 2 and 3
8	Last 3 digits divisible by 8
9	Sum of digits divisible by 9
10	Last digit 0

 Trick 1: Fast Divisibility Check

Example:

Is 735 divisible by 3?

7 + 3 + 5 = 15

15 divisible by 3

✅ Yes

 Trick 2: Even & Odd Rules

Operation	Result
Even + Even	Even
Odd + Odd	Even
Even + Odd	Odd
Odd × Odd	Odd
Even × Any	Even

 Trick 3: Prime Number Shortcut

Prime numbers have:

• Only 2 factors
• 1 and itself

Important primes:

2,3,5,7,11,13,17,19...

 Trick 4: HCF Shortcut

Formula:

0

Example:

Numbers = 12 and 18

HCF = 6
LCM = 36

6 × 36 = 216

12 × 18 = 216

✅ Verified

 Trick 5: Number of Factors

If:

1

Then:

2

Example:

72 = 2³ × 3²

Factors:

(3+1)(2+1)

4 × 3

✅ Answer = 12 factors

 Trick 6: Remainder Shortcut

Basic Rule:

If dividend < divisor

Then: Remainder = Dividend

Example:

5 ÷ 8

✅ Remainder = 5

 Important Observation Trick

For any number:

3

Very important for Bank Exams.

📖 Important Number System Shortcuts

Topic	Shortcut
Divisibility	Digit rules
Prime Numbers	Only 2 factors
HCF & LCM	Product relation
Factors	Power +1 method
Even/Odd	Pattern rules

 Practice Questions

1. Is 864 divisible by 9?
2. Find HCF of 18 and 24
3. Find LCM of 12 and 15
4. Number of factors of 36 = ?
5. Even + Odd = ?

✅ Answers

1. Yes
2. 6
3. 60
4. 9
5. Odd

🎯 Preparation Strategy:
Practice divisibility rules, prime numbers, HCF & LCM shortcuts, and factor counting methods daily to improve arithmetic speed and simplification solving ability.

“Strong Basics in Number System Make Advanced Aptitude Problems Easier.”

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Bank Exam Speed Maths Master Series