Matty F wrote:

So, round or truncate? I am not talking about prices in a shop, but
measurements.

Depends what you're going to do with the result. If machining two
components, say, and you know whether the fit should be tight or loose
you use this to adjust your numbers. If these components are going to be
a shrink or push fit then you'd make the inner one larger and the outer
one smaller. If there's to be a sliding fit then the reverse would apply.

--
Scott

Where are we going and why am I in this handbasket?