SSC CGL Maths Short Tricks and Formulas

Author at PW
May 21, 2025
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Preparing for SSC CGL math requires more than just practice. It is about using your brain smartly. Maths, especially, needs speed and accuracy. This is where knowing maths tricks will save you in competitive exams. The Quantitative Aptitude section can be tough, but with the right approach, you can score well. Math is like a game that needs patience, logic, and quick thinking. Let's learn how to win this game. We will cover SSC CGL Maths Short Tricks and Formulas

 This will help you solve questions more quickly and efficiently, saving you valuable time. These techniques are tried and tested, used by top-performing students, and explained here in the simplest terms to ensure that they are easily understood by everyone. 

Check Out: SSC Books

Maths Tricks for Competitive Exam

Before jumping into the tricks, build these basic skills:

  • Learn multiplication tables up to 30

  • Memorize squares up to 50

  • Remember cubes up to 20

  • Know all algebra formulas

  • Understand 2D and 3D shape formulas

  • Every second counts in SSC CGL’s Quant section.

  • Simple patterns mean fewer slip-ups.

  • Clear steps calm exam stress.

Integrating maths tricks for competitive exams into your routine makes solving complex questions feel effortless.

Quick Calculation Tricks for SSC CGL

Multiplication Shortcuts

Method 1: Multiplying with 999

Example: 654 × 999

Step 1: Subtract 1 from 654 = 653 Step 2: Subtract each digit of 653 from 9 (9 - 6) = 3 (9 - 5) = 4 (9 - 3) = 6

Final answer: 653346

This works because 999 = 1000 - 1, so 654 × 999 = 654 × (1000 - 1) = 654000 - 654 = 653346

Method 2: Multiplying with 11

Example: 43 × 11

For two-digit numbers:

  • Write the last digit (3) as it is

  • Add the two digits (4 + 3 = 7)

  • Write the first digit (4) as it is

  • Answer: 473

For three-digit numbers like 652 × 11:

  • Last digit stays: 2

  • Add 2 + 5 = 7

  • Add 5 + 6 = 11 (write 1, carry 1)

  • First digit 6 + carried 1 = 7

  • Answer: 7172

Check Out: SSC CGL Maths Book

Crisscross System of Multiplication

For multiplying two 2-digit numbers:

Example: 23 × 12

 

Step 1: Multiply ones digits: 3 × 2 = 6 Step 2: Cross multiply and add: (2 × 2) + (3 × 1) = 7 Step 3: Multiply tens digits: 2 × 1 = 2 Answer: 276

This method works for larger numbers too.

Squares and Cubes Up To 40

Memorizing squares and cubes will save you lots of time in the exam:

Number

Square

Cube

Number

Square

Cube

1

1

1

21

441

9,261

2

4

8

22

484

10,648

3

9

27

23

529

12,167

4

16

64

24

576

13,824

5

25

125

25

625

15,625

6

36

216

26

676

17,576

7

49

343

27

729

19,683

8

64

512

28

784

21,952

9

81

729

29

841

24,389

10

100

1,000

30

900

27,000

11

121

1,331

31

961

29,791

12

144

1,728

32

1,024

32,768

13

169

2,197

33

1,089

35,937

14

196

2,744

34

1,156

39,304

15

225

3,375

35

1,225

42,875

16

256

4,096

36

1,296

46,656

17

289

4,913

37

1,369

50,653

18

324

5,832

38

1,444

54,872

19

361

6,859

39

1,521

59,319

20

400

8,000

40

1,600

64,000

Important Algebraic Formulas

Here are the most important algebraic formulas you need to memorize:

Formula

Description

(a + b)² = a² + 2ab + b²

Square of sum

(a - b)² = a² - 2ab + b²

Square of difference

a² - b² = (a + b)(a - b)

Difference of squares

(a + b)³ = a³ + 3a²b + 3ab² + b³

Cube of sum

(a - b)³ = a³ - 3a²b + 3ab² - b³

Cube of difference

a³ + b³ = (a + b)(a² - ab + b²)

Sum of cubes

a³ - b³ = (a - b)(a² + ab + b²)

Difference of cubes

(a + b + c)² = a² + b² + c² + 2ab + 2bc + 2ca

Square of trinomial

If a + b + c = 0, then a³ + b³ + c³ = 3abc

Special case

Check Out: SSC Previous Year Question Paper

Square and Cube Tricks

Finding Squares Quickly

Duplex Method for Squares:

Example: (207)²

Break it down:

  • 2² = 4

  • 2 × 0 × 2 = 0

  • 2 × 7 × 2 + 0² = 28

  • 0 × 7 × 2 = 0

  • 7² = 49

Combine: 42849

Formula Method: Use (a + b)² = a² + 2ab + b²

Example: 1009² = (1000 + 9)² = 1000² + 2(1000)(9) + 9² = 1000000 + 18000 + 81 = 1018081

Finding Cubes

Example: 16³

Write as: 1 6 36 216 Calculate: 4096

Finding Square Roots and Cube Roots

Square Root Method:

Example: √7744

  1. The number ends with 4, so square root ends with 2 or 8

  2. 7744 is between 80² (6400) and 90² (8100)

  3. So answer is either 82 or 88

  4. Since 7744 is closer to 8100, the answer is 88

Cube Root Method:

Example: ∛1404928

  1. The number ends with 8, so the cube root ends with 2

  2. 1404 is between 11³ (1331) and 12³ (1728)

  3. Since 1404 is closer to 1331, the answer is 112

2D Shapes Formulas

Shape

Area

Perimeter

Rectangle

ab

2(a + b)

Square

4a

Triangle

½ × b × h

a + b + c

Circle

πr²

2πr

Parallelogram

ah

2(a + b)

Rhombus

½ d₁d₂

4a

Trapezium

½ × h × (a + b)

Sum of all sides

3D Shapes Formulas

Solid

Volume

Total Surface Area

Cube

6l²

Cuboid

lbh

2(lb + bh + hl)

Cylinder

πr²h

2πr(r + h)

Cone

⅓πr²h

πr(l + r)

Sphere

⅘πr³

4πr²

Check Out: SSC CGL Previous Year Paper

Percentage Tricks and Fraction Conversions

Common Fraction to Percentage Conversions:

Fraction

Percentage

Fraction

Percentage

1/2

50%

3/5

60%

1/3

33⅓%

2/3

66⅔%

1/4

25%

3/4

75%

1/5

20%

2/5

40%

1/6

16⅔%

5/6

83⅓%

1/7

14⅖%

2/7

28⅗%

1/8

12½%

3/8

37½%

1/9

11⅑%

2/9

22⅖%

1/10

10%

4/5

80%

1/11

9⅑%

4/7

57⅐%

1/12

8⅓%

5/8

62½%

Quick Percentage Calculation:

To find 10% of any number, just move the decimal point one place left. Example: 10% of 350 = 35

For 5%, take half of 10%: Example: 5% of 350 = 17.5

For 20%, double the 10%: Example: 20% of 350 = 70

For 25%, add 5% to 20% or find ¼ of the number: Example: 25% of 350 = 70 + 17.5 = 87.5

Vedic Mathematics Tricks for Speed Calculation

1. Multiplication by 9, 99, 999, etc.

Example: 45 × 99 Step 1: Subtract 1 from multiplier: 99 - 1 = 98 Step 2: Subtract 45 from 100: 100 - 45 = 55 Answer: 4455

2. Squaring numbers ending in 5

Example: 35² Step 1: Multiply the first digit by the next higher digit: 3 × 4 = 12 Step 2: Append 25 to the result: 1225 Answer: 35² = 1225

3. Multiplication using the base method

Example: 96 × 97 Step 1: Choose base (100) Step 2: Difference from base: 96 is 4 less, 97 is 3 less Step 3: Subtract sum of differences from first number: 96 - (4 + 3) = 89 Step 4: Multiply the differences: 4 × 3 = 12 Answer: 9312

4. Division shortcuts

For dividing by 5: Step 1: Multiply by 2. Step 2: Move decimal point left once Example: 76 ÷ 5 = (76 × 2) ÷ 10 = 152 ÷ 10 = 15.2

Check Out: Mathematics Formula Book

Tips to Excel in the SSC CGL Math Section

  1. Learn Strong Basics: Understand fundamental concepts thoroughly before moving to shortcuts.

  2. Learn Formulas: Know when and how to apply each formula - memorization without understanding won't help.

  3. Read Questions Carefully: Take time to understand what's being asked before solving.

  4. Find Patterns: Many SSC CGL questions follow similar patterns - recognize them to save time.

  5. Practice Daily: Solve different types of problems regularly to build speed and confidence.

  6. Create Tables: Use visual aids for complex problems with lots of data.

  7. Manage Time: Allocate time wisely - skip difficult questions and come back later.

  8. Use Approximations: When appropriate, use estimations to quickly eliminate wrong options.

  9. Double-Check: In multiple-choice questions, verify your answer by substituting back into the original problem.

  10. Learn from Mistakes: Check your errors in practice tests to avoid repeating them.

Subject-Wise SSC CGL Math Preparation

It is important for you to understand which subject requires the most preparation so that you can allocate your time effectively and efficiently to achieve good results. 

Arithmetic

  • Focus on percentage, ratio & proportion, profit & loss, simple & compound interest

  • Learn shortcut formulas for time & work and time & distance problems

  • Practice problems on averages, mixtures & allocations

Algebra

  • Master linear equations, quadratic equations, and inequalities

  • Practice simplification using algebraic identities

  • Focus on sequence & series problems

Geometry

  • Memorize properties of triangles, circles, and quadrilaterals

  • Practice coordinate geometry problems

  • Learn trigonometric ratios and identities

Data Interpretation

  • Practice reading tables, graphs, and charts quickly

  • Learn shortcuts for calculating percentages and ratios from data

  • Develop estimation skills for quick approximations

Success in competitive exams comes with consistent practice. Apply these math tricks for competitive exams daily. Remember that the more you practice, the better you'll get at speed maths tricks. These maths formulas for SSC CGL will help you solve problems faster.

The key to mastering algebra tricks for SSC CGL is understanding when to use which formula. With these maths tricks with answers, you'll save valuable time during your exam.

Practice makes perfect! Keep solving problems using these math shortcuts, and you'll see improvement in both speed and accuracy.

Read More: SSC CGL Study Material with Preparation Strategy

SSC CGL Maths Tricks FAQs

1. How do I handle ratio and proportion questions quickly?

Convert ratios to fractions (a:b = a/(a+b) and b/(a+b)), then multiply by the total to get each part without trial-and-error.

2. What’s the best way to practice these speed maths tricks?

Daily timed drills focusing on one trick, weekly mock tests under exam conditions, and maintaining an error log for formulas you forget.

3. How can I solve data interpretation questions faster?

Read axes and titles first, identify key trends, then apply averages or percentage change shortcuts rather than recomputing each value

4. How do I multiply by 999 without long multiplication?
Subtract 1 from your number (A), then for each digit of A subtract 9 (to get B). The answer is A concatenated with B.

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