Android - exact mathematical calculation

Question

I have got a Problem, I am developing an Application which should be able to do some mathematic calculations. These calculations have to be exact (or rather not obviously wrong)

Answer 1

Use a BigDecimal for precise floating point calculations. Setting the scale allows you to specify precisely how far out you want to go for output.

import java.math.BigDecimal;

class Test{

        public static void main(String[] args){
                BigDecimal a = new BigDecimal("3.048");
                BigDecimal b = new BigDecimal(1000);
                BigDecimal c = a.divide(b).setScale(6);
                System.out.println(c); //0.003048
        }
}