Approximation and simplification tricks for bank exams can save you 5 to 6 minutes in the Quant section of SBI PO and IBPS PO. In this post, you will learn 8 approximation and simplification tricks for bank exams, with solved examples, so you can solve each question in under 30 seconds. The secret is never to calculate fully, but to round smartly and use fractions. These tricks are most useful for Prelims, and the same speed techniques help in Mains DI calculations too.
Trick 1: Round to the nearest friendly number
SBI PO simplification questions or approximation questions rarely need exact answers, because the options are usually far apart. Convert ugly numbers into round ones.
Example: 49.98% of 799.8 + 24.95% of 1203 ≈ ?
- 49.98% of 799.8 ≈ 50% of 800 = 400
- 24.95% of 1203 ≈ 25% of 1200 = 300
- Answer: 700
These approximation and simplification tricks for bank exams only work if you have the fraction-percentage table memorized, so start here.
Trick 2: Memorize the fraction-percentage table
This is the single biggest time saver.
| Fraction | % | Fraction | % |
|---|---|---|---|
| 1/2 | 50 | 1/8 | 12.5 |
| 1/3 | 33.33 | 1/9 | 11.11 |
| 1/4 | 25 | 1/11 | 9.09 |
| 1/5 | 20 | 1/12 | 8.33 |
| 1/6 | 16.67 | 1/16 | 6.25 |
| 1/7 | 14.28 | 1/20 | 5 |
Example: 14.28% of 497 + 12.5% of 642 ≈ ?
- 14.28% = 1/7, so 497 ÷ 7 = 71
- 12.5% = 1/8, so 642 ÷ 8 ≈ 80
- Answer: ≈ 151
Trick 3: Know squares and cubes cold
Learn squares up to 30 and cubes up to 15. For squares near 50 or 100, use (a ± b)².
Example: 49² = (50 − 1)² = 2500 − 100 + 1 = 2401
For a² − b², use (a − b)(a + b):
Example: 87² − 13² = (87 − 13)(87 + 13) = 74 × 100 = 7400
Trick 4: Multiplication shortcuts
- × 5 → divide by 2, then × 10.
- Even number: 348 × 5 = 174 × 10 = 1740
- Odd number: 347 × 5 = 173.5 × 10 = 1735
- × 25 → (divide by 4, then × 100) 76 × 25 = 19 × 100 = 1900
- × 125 → (divide by 8, then × 1000) 64 × 125 = 8 × 1000 = 8000
- × 99 → (× 100 minus the number) 47 × 99 = 4700 − 47 = 4653
- × 11 → add adjacent digits and place the sum in the middle.
- Simple case: 53 × 11 = 5 (5+3) 3 = 583
- Carry case: if the sum is 10 or more, carry the 1 to the left digit. 78 × 11 = 7 (7+8=15) 8 → (7+1) 5 8 = 858
Trick 5: Follow VBODMAS strictly
Most wrong answers in Simplification come from the wrong order of operations. The order is Vinculum (bar), Brackets, Of, Division, Multiplication, Addition, Subtraction.
Example: 18 + 12 ÷ 3 × 2 − 5
- 12 ÷ 3 = 4, then 4 × 2 = 8
- 18 + 8 − 5 = 21
Trick 6: Group and cancel before multiplying
Look for pairs that cancel or make round numbers first.
Example: (84 × 25) ÷ 7 + 36² ÷ 12
- (84 ÷ 7) × 25 = 12 × 25 = 300
- 36² ÷ 12 = 36 × 3 = 108
- Answer: 408
Trick 7: Compensate your rounding
If you round one number up, try to round the other down, so the errors cancel.
Example: 19.8 × 31.2 ≈ 20 × 31 = 620 (actual is 617.76, so the nearest option will still match)
Rounding both numbers up would give a larger error, so avoid that.
Trick 8: Cancel zeros and decimals early
Example: 1599.9 ÷ 16.01 × 4.98 ≈ ?
- 1600 ÷ 16 = 100
- 100 × 5 = 500
Common mistakes to avoid in approximation and simplification
- Rounding too aggressively. Keep the error under about 2%.
- Ignoring “of”, which means multiplication and comes before division.
- Wasting time on exact calculation when the options are far apart.
- Skipping square and cube revision. It costs you 10 to 15 seconds per question.
Related Posts:
Practice set (try in 30 seconds each)
- 39.99% of 650 + 15.01% of 1200 ≈ ?
- 1/9 of 1008 + 1/6 of 1206 ≈ ?
- 87² − 13² = ?
- 48 × 25 ÷ 6 + 15% of 400 = ?
- 2.99 × 79.8 ÷ 4.98 ≈ ?
Answers: 1) 440 2) 313 3) 7400 4) 260 5) 48
Final tip
Practice 20 questions daily with a timer. If you follow these approximation and simplification tricks for bank exams for two weeks, your speed will improve noticeably. For more Mains-level practice sets, join our Telegram community and read the next post: Square, Cube and Fraction-Percentage Chart (Free PDF).
