Oh wow, was using windows calc, but I see now that Construct wont accept floats with %.
n-360*floor(n/360) will do the same thing as "%" but preserve floating point numbers.
If you want only a positive angle as a answer:
n-360*floor(n/360) +360*(n<0)
heh figured Rojo, or one of the other brains would figure it out.
Guess you could also use int() there too.
450.33-360*int(450.33/360)