Rounding number up to half hour

[crxftw]

Hello, I've been trying to look everywhere but can't seem to find a solution how I can get my numbers rounded like that for example:

2.01 to 2.24 = 2
2.25 to 2.74 = 2.5
2.75 to 2.99 = 3

I would like to that in text box control source if possible, the value I need to get rounded comes from:

[Entitlement]+Sum([TotalHolidayHours])-[txtHolidayUsed]

Which for example is 23.1 right now, but in that case I'd need it to be 23. If it would be 23.3 then it's 23.5 already.

Thanks.

[alansidman]

Here is a solution in a query. You can apply the same expression in an unbound text box in a form if that is where you want it. See attached.

[crxftw]

Thanks, but found a solution that suits better for me:

=Round(2*([Entitlement]+Sum([TotalHolidayHours])-[txtHolidayUsed]),0)/2