Is it possible to store the values as pennies ? That would be integer numbers. The math in your system would need to be adapted, i.e fixed point math, instead of floating point. Maybe store even integers representing 1/1000 of a penny or some such. Still fixed point math, with some guard digits before you have to round. I.e. 1.23 [USD] would be 123 [Penny]. Or 123000 [1/1000th penny].