Why Speed Maths Matters
In competitive exams like SSC CGL, TSPSC Groups and Banking exams, you have less than 60 seconds per question on average. A student who can mentally calculate 45% of 360 in 5 seconds has a massive advantage over one who takes 30 seconds with pen-and-paper method.
Speed Maths — especially Vedic Mathematics techniques — can reduce your calculation time by 50–70%. Learning these tricks is one of the highest-return investments in your exam preparation.
⚡ Fact: Top scorers in SSC CGL spend less than 40 seconds on average per Quantitative Aptitude question. Speed Maths training is their secret weapon.
Trick 1: Multiplication by 11
Rule: Add the two digits and place the sum in the middle.
Example: 53 × 11 → 5 + 3 = 8 → Answer: 583
Example: 47 × 11 → 4 + 7 = 11 → write 1, carry 1 → Answer: 517
Practice this until it takes less than 3 seconds!
Trick 2: Squares of Numbers Ending in 5
Rule: Multiply the first digit by (first digit + 1), then write 25 at the end.
35² = 3 × 4 = 12 → Answer: 1225
75² = 7 × 8 = 56 → Answer: 5625
95² = 9 × 10 = 90 → Answer: 9025
Trick 3: Fast Percentage Calculation
Key principle: X% of Y = Y% of X
Use this when one percentage is easier to calculate than the other.
More shortcuts:
- 10% = divide by 10
- 5% = half of 10%
- 1% = divide by 100
- 15% = 10% + 5%
- 25% = divide by 4
- 33.33% ≈ divide by 3
Trick 4: Multiplication Near 100
Step 1: Difference from 100: 96→ -4, 97→ -3
Step 2: Left part: 96 - 3 = 93 (or 97 - 4 = 93)
Step 3: Right part: (-4) × (-3) = 12
Answer: 9312
Difference: +3 and +4. Left: 103+4 = 107. Right: 3×4 = 12. Answer: 10712
Trick 5: Divisibility Rules
| Divisible by | Rule | Example |
|---|---|---|
| 2 | Last digit is even | 348 ✓ |
| 3 | Sum of digits divisible by 3 | 123: 1+2+3=6 ✓ |
| 4 | Last 2 digits divisible by 4 | 1324: 24÷4=6 ✓ |
| 5 | Last digit is 0 or 5 | 375 ✓ |
| 6 | Divisible by both 2 and 3 | 132 ✓ |
| 8 | Last 3 digits divisible by 8 | 1000 ✓ |
| 9 | Sum of digits divisible by 9 | 729: 7+2+9=18 ✓ |
| 11 | (Sum of odd positions) - (Sum of even positions) = 0 or 11 | 2728: (2+2)-(7+8)≠ ✗ |
Trick 6: Approximation for Large Calculations
Most competitive exam questions allow approximation to ±1%. Round numbers smartly.
63² = 3969 exactly. Know squares up to 30 by heart: 16²=256, 17²=289, 18²=324...
Must memorize: Squares 1–30, Cubes 1–15, Square roots of perfect squares up to 400.
Trick 7: Ratio and Proportion Shortcuts
To find a value when ratios are given:
Total parts = 3+5 = 8. Value of 1 part = 80÷8 = 10. A = 3×10 = 30, B = 5×10 = 50.
This approach works for any ratio problem and takes under 15 seconds.
Trick 8: Compound Interest Shortcut
Or simply: CI = SI + (SI × r / 200)
Example: P=1000, r=10%, 2 years
SI = 200. Extra = 200×10/200 = 10. CI = 210
This is 3x faster than the standard formula.
Memory Tables You Must Know
Fraction-Percentage Equivalents
| Fraction | Percentage | Fraction | Percentage |
|---|---|---|---|
| 1/2 | 50% | 1/7 | 14.28% |
| 1/3 | 33.33% | 1/8 | 12.5% |
| 1/4 | 25% | 1/9 | 11.11% |
| 1/5 | 20% | 1/11 | 9.09% |
| 1/6 | 16.67% | 1/12 | 8.33% |
Daily Practice Plan for Speed Maths
- Warm-up (10 min): Mental multiplication of 2-digit numbers × single digit — do 20 problems daily
- Percentage practice (10 min): Calculate X% of Y for random values without a calculator
- Series completion (10 min): Number series — identify patterns quickly
- DI practice (20 min): Solve one full Data Interpretation set with a timer
- Mock test (30 min): Full Quantitative Aptitude section mock test with strict time limit
🎯 Goal: After 30 days of daily Speed Maths practice, most students improve their Quantitative Aptitude score by 8–12 marks. This could be the difference between selection and rejection.
Practice Speed Maths Mock Tests Free
Anil EduTech offers dedicated Speed Maths mock tests designed to improve your calculation speed. Our timed tests help you practice under real exam conditions. Track your improvement over time and compare with other aspirants on the leaderboard.
🚀 Start Free Speed Maths Test →