A better way to round off.

Round up for 5 or greater is a simple method of rounding off, but it introduces a bias.  See below to find out how to avoid the bias, as explained by the authoritative Math Forum.

There are two ways to round that are commonly taught. The rules we give in most of our answers are those taught to children (and commonly used by computers), because they are simpler but are sufficient for
most purposes. Where statistics matter, and where numbers that END
with the 5 are common, rounding to even is preferred.
When an even decimal (or any even number) is followed by a 5, you
round down. When an odd decimal is followed by a 5, you round up.
For example: 75.45 = 75.4, but 75.55=75.6. Or rounding to the nearest
10, 145 = 140, but 155 = 160.

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