This program asks for two numbers and the mathematical operator to use on them.
Calculator.java:
import java.util.Scanner; public class Calculator { public void run() { Scanner numberReader=new Scanner(System.in); Scanner textReader=new Scanner(System.in); double number1, number2; String operator, result, rounding1, rounding2; System.out.print("Enter first number: "); number1=numberReader.nextDouble(); System.out.print("Enter second number: "); number2=numberReader.nextDouble(); System.out.print("Operation: "); operator=textReader.nextLine(); numberReader.close(); textReader.close(); if(operator.equals("+")) { result=String.format("%.2f", (number1+number2)); rounding1=String.format("%.2f", (number1));//round to second decimal rounding2=String.format("%.2f", (number2)); System.out.println(rounding1+" + "+rounding2+" = "+result); } else if(operator.equals("-")) { result=String.format("%.2f", (number1-number2)); rounding1=String.format("%.2f", (number1)); rounding2=String.format("%.2f", (number2)); System.out.println(rounding1+" - "+rounding2+" = "+result); } else if(operator.equals("*")) { result=String.format("%.2f", (number1*number2)); rounding1=String.format("%.2f", (number1)); rounding2=String.format("%.2f", (number2)); System.out.println(rounding1+" * "+rounding2+" = "+result); } else if(operator.equals("/")) { result=String.format("%.2f", (number1/number2)); rounding1=String.format("%.2f", (number1)); rounding2=String.format("%.2f", (number2)); System.out.println(rounding1+" / "+rounding2+" = "+result); } else if(operator.equals("%"))//remainder { number1=(int)number1*1;//save value as int number2=(int)number2*1; System.out.println((int)number1+" % "+(int)number2+" = "+(int)number1%(int)number2); } else { System.out.println("Wrong value given"); } } public static void main(String[] args) { Calculator program = new Calculator(); program.run(); } }