text: 
  var grades = [43,34,23,56]
  
  var result
  
  console.log(grades);
  
  console.log("start");
  for (i=0;i<grades.length;i++) {
  
      grades[i]= grades[i]*2
  
  console.log(grades);
  }
  
  console.log("end");
  console.log(grades);
  
  
  