Rounding
Replacing a number with a nearby one that has fewer digits, such as 2.675 with 2.68.
Methods differ on exact halves: one common rule always rounds a half up, another rounds it to the nearest even digit, so 2.5 becomes 3 under the first and 2 under the second. Round once, at the end, because rounded figures added together do not always match the rounded total.
Where it comes up
- Rounding and precision lossDigits were dropped when a value was displayed, exported, or converted, and the file now holds the shortened number.
See also
- PrecisionFor numbers, how finely a value is recorded: 3.14159 carries more precision than 3.1. In matching and error detection the word has a second meaning: of everything that was flagged, how much was flagged correctly.
- Floating pointThe usual way computers store numbers with a fractional part, using a fixed number of binary digits. Most decimal fractions cannot be stored exactly, so 0.1 plus 0.2 comes out as 0.30000000000000004.
- IntegerA whole number with no fractional part, such as 42 or -7. It is the natural type for counts.