How to round a decimal value when working with context.expand number values?

I'm to verify values of an equation that is happening on the back end.

Example Values:
wages = 29250
divby = 11670
Should Equal = 2.5064267352 //which it does

QUESTION:  I need the result value I"m asserting is to = 2.51

def testValuea = context.expand( '${Properties#a}' ) as int //--11670
def testValueb = context.expand( '${Properties#b}' ) as int //--29250

result = (testValueb / testValuea)*100

//now my value is 250.64267352

QUESTION:  How do I get this to round to (3)?
Not sure where to use .Round(3) or if to use something else.

Thank you,
Rob