In Banking exams (IBPS/SBI), you cannot afford to waste time calculating squares like
48 × 48 on paper. Here are the 3 best tricks to calculate Squares and Square Roots
instantly.
Trick 1: Numbers Ending with 5
Example: 35²
1. 3 × 4 = 12
2. Append '25' → 1225
Trick 2: Base 50 Method
Golden Number is 25. Compare with 50, adjust with 25.
Example: 48² (-2 from 50)
1. 25 - 2 = 23
2. 2² = 04 → Answer: 2304
Trick 3: Square Root
| Question Ends With | Answer Ends With |
|---|---|
| 1 | 1 or 9 |
| 4 | 2 or 8 |
| 5 | 5 |
Example: Find √7921
1. Last digit is 1: So answer ends in 1 or 9.
2. Ignore last 2 digits: We are left with 79.
3. Nearest Square: Which square is close to 79?
8² = 64 (Low), 9² = 81 (High). Take the lower one: 8.
8² = 64 (Low), 9² = 81 (High). Take the lower one: 8.
4. Decision: Is answer 81 or 89?
Since 79 is closer to 81 (9²) than 64 (8²), pick the larger number.
Since 79 is closer to 81 (9²) than 64 (8²), pick the larger number.
👉 Answer: 89
Practice these tricks daily!