Rounding Calculator
Round any number to a chosen number of decimal places or significant figures. Compare rounding, floor, ceiling, and truncation side by side in real time.
How to Use the Rounding Calculator
- Enter the numbers or values in the input fields.
- The result is calculated and displayed automatically.
- Review the step-by-step solution or detailed breakdown.
- Copy the result or adjust inputs for a new calculation.
快速参考
| 从 | 到 |
|---|---|
| 2 + 3 | 5 |
| 12 × 12 | 144 |
| √144 | 12 |
| 2¹⁰ | 1,024 |
| π | 3.14159 |
| e | 2.71828 |
使用场景
- •Checking homework or exam answers quickly and accurately.
- •Verifying manual calculations in professional or academic work.
- •Learning mathematical concepts with instant visual feedback.
- •Performing quick computations during meetings or presentations.
公式
Round half-up: round 0.5 up. Floor: always round toward −∞. Ceiling: always round toward +∞. Truncate: drop fractional digits (round toward zero). Significant figures count all meaningful digits from the first non-zero digit.
常见问题
What is the difference between rounding and truncating?
Rounding picks the nearest value (e.g., 2.7 rounds to 3), while truncating simply removes extra digits (2.7 truncates to 2). Truncation always moves toward zero.
What are significant figures?
Significant figures are all digits that carry meaning, starting from the first non-zero digit. For example, 0.00340 has 3 significant figures (3, 4, and the trailing 0).
What is the difference between floor and ceiling?
Floor rounds down toward negative infinity (⌊2.3⌋ = 2, ⌊−2.3⌋ = −3). Ceiling rounds up toward positive infinity (⌈2.3⌉ = 3, ⌈−2.3⌉ = −2).