For bank exams like SBI PO and IBPS PO, the Quantitative Aptitude section is all about speed and accuracy. The questions are designed to test not just your knowledge, but your ability to perform quick calculations under pressure. This comprehensive guide will equip you with essential speed math tricks and strategies that can save you precious minutes and help you score higher.

1. Core Fundamentals First

Before applying any tricks, you must have a solid foundation. This is non-negotiable for success.

What to Master:

  • Tables: Up to 25.
  • Squares: Up to 50.
  • Cubes: Up to 20.
  • Fractions & Percentages: Memorize common conversions (1/7 ≈ 14.28%, 3/8 = 37.5%, etc.).

These are the building blocks. If you have to calculate 1/6 of 360, knowing that 1/6 = 16.67% is a shortcut, but knowing the fraction itself is the fastest way: (1/6) × 360 = 60.

2. Shortcuts for Simplification & Approximation

These sections often contain a large number of questions, making them crucial for boosting your score.

A. The Digital Sum Method

This technique (also known as Casting Out Nines) helps you check or eliminate options quickly, especially with multiplication and addition.

Example: Find the value of 748 × 242

Step 1: Find the digital sum of each number.
Digital sum of 748 = 7+4+8 = 19 → 1+9 = 10 → 1+0 = 1.
Digital sum of 242 = 2+4+2 = 8.

Step 2: Multiply the digital sums.
1 × 8 = 8. The digital sum of the answer must be 8.

Step 3: Check the options.

Option A: 181016 → 1+8+1+0+1+6 = 17 → 8. (Correct!)
Option B: 181026 → 1+8+1+0+2+6 = 18 → 9. (Incorrect)

B. Approximation for Decimal Values

Bank PO questions often involve decimals. Learn to round to the nearest whole number to get a close estimate.

Example: Solve √784.01 + 125.99 - 14.99

Approximate the values first.
√784 = 28
125.99 ≈ 126
14.99 ≈ 15
Calculation: 28 + 126 - 15 = 154 - 15 = 139

This is a highly effective strategy for time-sensitive problems.

3. Rapid Multiplication Techniques

Multiplication is a key skill. Beyond the base method, try these.

A. Criss-Cross Multiplication

This is a versatile method for multiplying two-digit numbers mentally.

Example: 42 × 35

  • Step 1: Multiply the last digits. 2 × 5 = 10. Write down 0 and carry over 1.
  • Step 2: Criss-cross and add. (4 × 5) + (2 × 3) = 20 + 6 = 26. Add the carried over 1: 26 + 1 = 27. Write down 7 and carry over 2.
  • Step 3: Multiply the first digits. 4 × 3 = 12. Add the carried over 2: 12 + 2 = 14. Write down 14.

Answer: 1470

4. Smart Division and Percentage Calculations

Percentages and fractions are heavily featured in DI.

A. Percentage Conversions

Knowing the fractional equivalents of percentages is non-negotiable.

Example: What is 37.5% of 800?

37.5% = 3/8
(3/8) × 800 = 3 × 100 = 300

This is far faster than 0.375 × 800.

B. Division by Approximation

Round the numbers to the nearest multiple or power of 10 to quickly estimate the quotient. This is especially useful in DI questions where exact answers aren't always needed.

5. Number Series and Data Interpretation (DI)

These sections are where speed math truly shines.

  • Number Series: Look for differences, squares, cubes, and prime numbers. With fast calculation, you can quickly spot the pattern.
  • DI: Learn to scan the data and use approximations. Don't calculate every single value; use a combination of mental math and logical reasoning. For example, if you need to find the average of a set of numbers, assume a middle value and calculate the difference to save time.

6. The Key to Success: Consistent Practice

These tricks are powerful, but they won't help if you can't recall them instantly. The only way to achieve this is through **daily practice**. Start with simple questions and gradually move to full-length mock tests, applying these shortcuts consistently. Our timed practice games are perfect for building the speed and reflexes you need.

Ready to get started?

Test your speed with our Timed Challenge and track your progress!