Definition:Rounding/Treatment of Half/Round Up

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Definition

Let $n \in \Z$ be an integer.

Let $x \in \R$ be a real number.


Consider the situation when $\dfrac x {10^n} + \dfrac 1 2$ is an integer.

That is, $\dfrac x {10^n}$ is exactly midway between the two integers $\dfrac x {10^n} - \dfrac 1 2$ and $\dfrac x {10^n} + \dfrac 1 2$.


The round up convention is that the larger of those two integers is used:

$X = 10^n \floor {\dfrac x {10^n} + \dfrac 1 2}$

where $X$ is the rounded value.


Sources