Rounding Numbers Calculator
Round numbers to any decimal place or whole number. Learn rounding rules.
Try:
How to Use
- Enter the number you want to round
- Select the place value to round to
- Click "Round" to see the result
- View the rounded number and explanation
What is Rounding Numbers Calculator?
Rounding is a mathematical process of replacing a number with an approximate value that has fewer digits. It's used to simplify numbers, make estimates, and express measurements with appropriate precision.
Formula
Standard Rounding Rules:
Look at the digit immediately after the rounding position:
• If it's 0, 1, 2, 3, or 4 → Round DOWN
• If it's 5, 6, 7, 8, or 9 → Round UP
Examples
- 3.14159 → 3.14 (to hundredths)
- 1,234 → 1,200 (to hundreds)
- 5.678 → 6 (to whole number)
- 0.0456 → 0.046 (to thousandths)
FAQ
What does it mean to round to a place value?
Rounding to a place value means adjusting the number so that digit at that position is approximate, and all digits after it become zero (for whole numbers) or are removed (for decimals).
What happens when the digit is exactly 5?
In standard rounding, 5 rounds up. For example, 2.5 rounds to 3. Some scientific contexts use 'banker's rounding' where 5 rounds to the nearest even number, but this calculator uses standard rounding.
When should I use rounding?
Use rounding for estimates, simplifying calculations, displaying currency amounts, expressing measurements with appropriate precision, and making numbers easier to communicate.