Why calculate like a student when you can calculate like a calculator? In competitive exams, the Simplification and Approximation sections test one thing above all else: how fast your brain can multiply. Candidates who rely on traditional long multiplication are at a systematic disadvantage — they might know the same concepts as toppers, but they're solving each question in 45-60 seconds while toppers are done in 15-20.
The 8 multiplication shortcuts below are carefully selected based on IBPS PO, SBI Clerk, and SSC CGL question patterns from 2020-2024. Each trick appears directly in exam questions multiple times every year. Master them, and you'll watch your Quantitative Aptitude marks change dramatically.
1. Magic of 11 — Multiply Any Number by 11 in Seconds
This is the most elegant mental math trick for 2-digit numbers. Works 100% of the time in under 3 seconds.
Exam Application: "Find 63 × 11" is directly tested in Simplification. Also useful in DI calculation chains.
2. Unit Sum = 10, Same Tens Digit — Instant Product!
This unlocks instant multiplication for pairs like 43 × 47, 61 × 69, 72 × 78. Fastest trick for these specific number combinations.
Condition: Same tens digit AND unit digits sum to 10.
3. Multiply by 5, 25, 50 — Use Division Instead!
These numbers are halves of powers of 10. Use division to avoid traditional multiplication entirely.
Exam Tip: In Approximation questions like "348 × 49.87 ≈ ?", round 49.87 to 50, then use × 50 trick: 348 × 50 = 17,400.
4. Base 100 Method — Numbers Near 100
Nikhilam Sutra from Vedic Math. Fastest when both numbers are within ±15 of 100.
5. Universal 2-Digit × 2-Digit — The I-X-I (Criss-Cross) Method
Works for ANY two 2-digit numbers. This is the go-to when no special trick applies.
6. Multiply by 99, 999 — The Complement Method
Logic: n × 99 = n × (100-1) = 100n - n. Eliminate the special-trick confusion.
7. Split & Merge — Most Practical General Method
Split the multiplier into convenient parts when no other trick applies.
8. Double & Half Method — For Decimal Multipliers
Eliminates decimals by doubling one factor and halving the other.
Quick Decision Guide: Which Trick for Which Question?
- One number is 11 👉 Trick 1
- Unit digits sum to 10, same tens 👉 Trick 2
- One number is 5/25/50 👉 Trick 3
- Both numbers near 100 👉 Trick 4
- One number is 99/999 👉 Trick 6
- One number ends in .5 👉 Trick 8
- No special pattern 👉 Trick 7 or Trick 5
Common Mistakes & How to Avoid Them
- Forgetting carry in Trick 1: When digit sum > 9, always carry 1 to the left digit.
- Wrong 2-digit format in Trick 2: If unit product < 10, write as "09" not "9" (e.g., 61 × 69 units=1 × 9=09, not plain 9).
- Using slow methods for approximation: You only need 2-3 significant figures. Stop calculating once you have enough precision to select the right MCQ option.
- Not doing unit-digit verification: Always quickly check that the units digit of your answer matches the expected units digit. Catches 80% of arithmetic errors instantly.
FAQ
Q: Which 3 tricks give the most return on investment for IBPS Prelims?
A: Tricks 3 (×5/25/50), 5 (Criss-cross), and 7 (Split & Merge) together cover 90% of Simplification
calculations. Master these first, then add the others.
Q: How do I build the reflex to choose the right trick quickly?
A: Deliberate practice with timing. Use Ikkish Prep's Simplification Quiz timed mode. Start slow,
consciously apply tricks. After 200+ questions, the right trick selection becomes automatic — faster
than your conscious mind can "decide."
Practice makes perfect! Start your Simplification Quiz on Ikkish Prep now and apply one new trick per day until all 8 are instinctive reflexes.