Round numbers to decimal places, significant figures, or nearest integer. Choose from multiple rounding methods including banker's rounding.
Rounded Value
3.14
2 decimal places
| Decimal Places | Rounded Value |
|---|---|
| 0 places | 3 |
| 1 places | 3.1 |
| 2 places | 3.14 |
| 3 places | 3.142 |
| 4 places | 3.1416 |
| 5 places | 3.14159 |
| Method | Result |
|---|---|
| standard | 3.14 |
| half even | 3.14 |
| up | 3.15 |
| down | 3.14 |
| truncate | 3.14 |
2.5 with different methods:
3.5 with different methods:
Rounded Value
3.14
2 decimal places
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Practice with 3 problems to test your understanding.
Rounding simplifies numbers to a specified precision. Standard rounding: digits 5-9 round up, 0-4 round down. For 3.567 to one decimal: 3.6 (7 rounds up). Round to nearest 10: 3,567 becomes 3,570. Significant figures count from the first non-zero digit. Always consider the digit after your rounding position.
Rounding is the process of replacing a number with an approximation that has fewer significant digits. It simplifies numbers for easier communication, calculation, or representation while maintaining reasonable accuracy. Different rounding rules (standard, ceiling, floor, banker's) serve different purposes in mathematics, science, and finance.
Rounding simplifies numbers to a specified precision. Standard rounding: digits 5-9 round up, 0-4 round down. For 3.567 to one decimal: 3.6 (7 rounds up). Round to nearest 10: 3,567 becomes 3,570. Significant figures count from the first non-zero digit. Always consider the digit after your rounding position.
Standard/Half-Up: rounds 0.5 up. Half-Even (Banker's): rounds 0.5 to nearest even number, reduces bias. Round Up (Ceiling): always rounds up. Round Down (Floor): always rounds down. Truncate: removes decimal places without rounding.
Banker's rounding (half-even) rounds 0.5 to the nearest even number. So 2.5 rounds to 2, but 3.5 rounds to 4. This reduces cumulative rounding bias in financial calculations where you round many numbers.
Significant figures are the meaningful digits in a number. Leading zeros are not significant. For example, 0.00456 has 3 sig figs. Trailing zeros after decimal are significant (4.50 = 3 sig figs). Used in science to show measurement precision.
Divide by the rounding unit, round to nearest integer, then multiply back. Example: 1234 to nearest 100 = round(1234/100) × 100 = round(12.34) × 100 = 12 × 100 = 1200.
Floating-point numbers can't represent all decimals exactly. 0.1 + 0.2 = 0.30000000000000004 in most languages. Use integer cents for money, libraries like decimal.js for precision, or round only at final display.
Last updated: 2025-01-15
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Rounded Value
3.14
2 decimal places