Definition
Rounding
A rule for swapping a number for a simpler nearby approximation.
Continue from this idea into connected AXIO math.
Boundary check: 3,476 rounds to 3,500; the two numbers are not exactly equal.
What it means
First choose the place you are rounding to. Then decide which allowed value is nearest. For nearest-place rounding, the digit immediately to the right tells which way to go; an exact halfway case follows the stated tie rule.
Remember it
Choose the place, then land on the nearest allowed value.
Example
Round 3,476 to the nearest hundred. It lies between 3,400 and 3,500 and is closer to 3,500, so 3,476 rounds to 3,500.
Watch for
A rounded number is usually an approximation, not another exact name for the original number: 3,476 ≠ 3,500.
Common mix-up
Rounding is not simply cutting off digits. The discarded part can make the kept digit increase.
Exact meaning
Rounding selects an allowed approximation according to a named place, unit, or accuracy rule. In nearest-place rounding, the chosen value is the closest multiple of that place.