Take the 2-minute tour ×  Possible Duplicate: 0.25 mile or 0.25
miles?  When writing out a quantity and then a noun what is the
correct form for decimals?  1 day 2 days .5 days?  It seems that
if you were to say "half day" then the singular is reasonable
but if you were to day "point five days" that also seems
correct.  share|improve this question add comment  marked as
duplicate by ShreevatsaR, Mehper C. Palavuzlar, RegDwigнt,
Kosmonaut Sep 24 '10 at 13:17   1 Answer  You are right, one
would say 'half a day'. One would also say '.5 of a day', but
'.5 days'. The difference is that in the '.5 days', the verb day
is described by a number other than one, in the other example,
you've effectively got 'one .5 of a day', which means that day
is qualified it with one, thus making it is singular.
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