find square root of 15.25 by division method upto 3 decimal
The Correct Answer and Explanation is:
√15.25 by Division Method (up to 3 decimal places)
We will now find the square root of 15.25 using the long division method, step-by-step.
✅ Answer:
√15.25 ≈ 3.905 (correct to 3 decimal places)
📘 Explanation
The long division method is a traditional technique used to find square roots of numbers (especially non-perfect squares) up to a desired number of decimal places. It is particularly useful when calculators are not allowed, such as in exams.
Here is how we find √15.25 step by step:
1. Group the Digits:
- Write 15.25 as 15.25 00 00 (adding pairs of zeros for decimal places).
- Group digits in pairs from the decimal point: 15 | 25 | 00 | 00
2. Find the Largest Square ≤ First Group (15):
- 3² = 9 and 4² = 16 → use 3
- Put 3 as the first digit of the root.
- Subtract 9 from 15 → remainder = 6
- Bring down next pair → new dividend = 625
3. Double the root (3 → 6), find next digit (D):
- Try (60 + D) × D ≤ 625
- Try D = 9: (60 + 9) × 9 = 69 × 9 = 621
- It’s valid → next digit is 9
- Root so far = 3.9
- Subtract: 625 – 621 = 4
- Bring down next pair → 400
4. Double root (3.9 → 78), find next digit:
- Try (780 + D) × D ≤ 400
- Try D = 0 → 780 × 0 = 0 → fits
- Next digit = 0 → Root = 3.90
- Subtract: 400 – 0 = 400
- Bring down next pair → 40000
5. Double root (3.90 → 780), find D:
- Try D = 5: (7800 + 5) × 5 = 7805 × 5 = 39025
- Fits → next digit is 5
- Final root = 3.905
Hence, √15.25 ≈ 3.905 (correct up to 3 decimal places).
