Java tutorial
//package com.java2s; import java.math.BigDecimal; public class Main { public static double mul(double value1, double value2) { BigDecimal b1 = BigDecimal.valueOf(value1); BigDecimal b2 = BigDecimal.valueOf(value2); return b1.multiply(b2).doubleValue(); } public static double mul(String value1, String value2) { BigDecimal b1 = new BigDecimal(value1); BigDecimal b2 = new BigDecimal(value2); return b1.multiply(b2).doubleValue(); } }