Rounding Calculator
This calculator allows you to round a number to the nearest integer, 10, 100, or any place value you choose.
Understanding Rounding
Rounding a number means approximating it to the nearest desired place value.
Formula:
Rounded Number = Math.round(Number ÷ Place) × Place
Example: Round 347 to nearest 10 → Math.round(347 ÷ 10) × 10 = 35 × 10 = 350
How the Calculator Works
The calculator automatically:
Step 1: Takes input: number and rounding place value
Step 2: Applies the rounding formula
Step 3: Displays the rounded number instantly
Examples
1. 347 → nearest 10 = 350
2. 347 → nearest 100 = 300
3. 12.678 → nearest 0.1 = 12.7
4. 12.678 → nearest 0.01 = 12.68
5. 4567 → nearest 1000 = 5000
Why Rounding Matters
Rounding is essential in daily life for money, measurements, statistics, and reporting values with appropriate precision.
Common Mistakes to Avoid
- Forgetting which place to round to
- Using floor/ceil instead of round for general rounding
- Confusing decimal places with whole numbers
Important: Standard rounding rounds 5 and above up, below 5 down.
Correct: Use Math.round() for standard rounding, not Math.floor() or Math.ceil().
Frequently Asked Questions
Can I round negative numbers?
Yes. Negative numbers follow the same rounding rules using absolute values.
Can I round to decimals?
Yes. Select 0.1 or 0.01 for decimal rounding.
What happens if the number is exactly in the middle?
The calculator rounds up (standard rounding rule).
Conclusion
This rounding calculator is a quick and effective tool to round numbers to the desired place value, making calculations, reporting, and estimations easy and accurate.