text: // Read number1, operator and number2 from HTML page
  function getValuesFromCalculator1(){
      //Read values
      let number1 = parseInt(document.getElementById("number1").value);
      let number2 = parseInt(document.getElementById("number2").value);
      let operator1 = document.getElementById("operator1").value;
  
      // alert("Read values: " + number1 + operator + number2)
      // Write result to HTML page
      let returnValue = calculate(number1, operator1, number2);
  
      document.getElementById("result").innerHTML = returnValue;
  
  }
  
  //This function makes calculations
  function calculate(numberX, operator1, numberY){
      let returnValue = 0;
      switch (operator1){
          case "+":
              returnValue = numberX + numberY;
              break;
          case "-":
              returnValue = numberX - numberY;
              break;
          case "*":
              returnValue = numberX * numberY;
              break;
          case "/":
              returnValue = numberX / numberY;
              break;
      }
      return returnValue;
  }
  function Increase1() {
  
      let userinput=parseInt(document.getElementById("number3").value);
      userinput=1+userinput;
      document.getElementById("number3").value=userinput;
  }
  function Decrease1() {
  
      let userinput=parseInt(document.getElementById("number3").value);
      userinput=userinput-1;
      document.getElementById("number3").value=userinput;
  }
  function Increase2() {
  
      let userinput=parseInt(document.getElementById("number4").value);
      userinput=1+userinput;
      document.getElementById("number4").value=userinput;
  }
  function Decrease2() {
  
      let userinput=parseInt(document.getElementById("number4").value);
      userinput=userinput-1;
      document.getElementById("number4").value=userinput;
  }
  function getValuesFromCalculator2(){
      let number3 = parseInt(document.getElementById("number3").value);
      let number4 = parseInt(document.getElementById("number4").value);
      let operator2 = document.getElementById("operator2").value;
  
      let returnValue = calculate(number3, operator2, number4);
  
      document.getElementById("result2").innerHTML = returnValue;
  
  }
  
  function calculate(numberX, operator2, numberY){
      let returnValue = 0;
      switch (operator2){
          case "+":
              returnValue = numberX + numberY;
              break;
          case "-":
              returnValue = numberX - numberY;
              break;
          case "*":
              returnValue = numberX * numberY;
              break;
          case "/":
              returnValue = numberX / numberY;
              break;
      }
      return returnValue;
  }
  function getValuesFromCalculator3(){
      let number5 = parseInt(document.getElementById("number5").value);
      let number6 = parseInt(document.getElementById("number6").value);
      const form = document.getElementById("selection");
      let operator3 = form.elements["sel"].value;
      let returnValue = calculate(number5, operator3, number6);
  
      document.getElementById("result3").innerHTML = returnValue;
  
  }
  
  function calculate(numberX, operator3, numberY){
      let returnValue = 0;
      switch (operator3){
          case "+":
              returnValue = numberX + numberY;
              break;
          case "-":
              returnValue = numberX - numberY;
              break;
          case "*":
              returnValue = numberX * numberY;
              break;
          case "/":
              returnValue = numberX / numberY;
              break;
      }
      return returnValue;
  }