The Quantitative Aptitude section of the SSC CGL exam is a race against the clock. Simply knowing the formulas isn't enough; you need to solve problems accurately and, most importantly, quickly. Mastering speed calculation techniques is the single most effective way to save precious time and significantly improve your score. This guide covers essential methods and tricks to help you calculate faster than ever before.

1. The Fundamentals: Strong Foundation is Key

Before jumping into tricks, ensure you have these basics down cold. They are the foundation of all speed math techniques.

What to Memorize:

  • Tables: Up to 20.
  • Squares: Up to 30.
  • Cubes: Up to 15.
  • Fractions & Percentages: Common conversions (e.g., 1/4 = 25%, 1/8 = 12.5%).

Having these committed to memory allows you to recognize patterns and avoid lengthy calculations.

2. Multiplication Shortcuts

Multiplication is a cornerstone of quantitative aptitude. Here are some of the most useful tricks.

A. Multiplying by 5, 25, 125

Instead of direct multiplication, use powers of 10.

Example: 48 × 25

Remember that 25 = 100/4.
48 × 25 = 48 × (100/4)
= (48/4) × 100
= 12 × 100 = 1200

B. Base Method for Numbers Near 100

This Vedic math technique is perfect for multiplying numbers like 97 and 94.

Example: 97 × 94

Step 1: Find the difference from the base (100).
97 → -3
94 → -6

Step 2: Add diagonally or subtract the differences.
97 - 6 = 91 (This is the first part of the answer)

Step 3: Multiply the differences.
(-3) × (-6) = 18 (This is the last part)

Answer: 9118

3. Squaring and Square Roots

Calculating squares quickly is a game-changer.

A. Squaring Numbers Ending in 5

This is a classic and simple trick.

Example: 75²

Step 1: The last two digits are always 25.
Step 2: Take the first digit (7) and multiply it by the next consecutive integer (8).
7 × 8 = 56

Answer: 5625

B. Finding Square Roots of Perfect Squares

This method works for perfect squares up to 4 digits.

Example: Find √3249

Step 1: The number ends in 9. This means the root must end in 3 or 7.

Step 2: Ignore the last two digits (49). The remaining number is 32.

Step 3: Find the perfect square just below 32. That's 25 (5²). So the first digit is 5.

Step 4: The answer is either 53 or 57. To decide, multiply the first digit (5) by the next integer (6). 5 × 6 = 30. Since 32 is greater than 30, pick the larger digit: 7.

Answer: 57

4. Smart Division and Percentages

Many SSC CGL problems involve percentages. Use fractional conversions to simplify.

Example: Find 16.67% of 420

Remember that 16.67% is approximately 1/6.
16.67% × 420 ≈ (1/6) × 420 = 70

This is much faster than converting to a decimal.

5. General Mental Math Strategies

  • Breakdown & Simplify: To add 347 + 198, think 347 + 200 - 2 = 547 - 2 = 545.
  • Digital Sum (Casting Out Nines): Use this to verify answers in multiple-choice questions. If the sum of the digits of a number equals 9, it's divisible by 9. This can quickly eliminate wrong options.
  • Rounding: For estimation, round numbers to the nearest 10 or 100 to quickly get a ballpark figure.

6. The Importance of Practice

Speed math tricks are useless if you don't practice them regularly. Incorporate these techniques into your daily study routine. Use our practice games to build the necessary speed and reflexes. The goal is to make these shortcuts second nature so you can apply them instantly in the exam.

Ready to put your skills to the test?

Try our Timed Challenge to practice speed calculations under exam-like conditions!