package rocks.zipcode.calcskin; public class CalcEngine { CalcEngine() { } public double add(double v, double v1) { return (v+v1);} public double subtract(double v, double v1) { return (v-v1);} public double multiply(double v, double v1) { return (v*v1);} public double divide(double v, double v1) { return (v/v1);} }