Javascript/JS - Referring to classes and variables dynamically within a change event loop

I'm trying to cut down this list of class change functions to one neat loop using an array for the class names used in the change event.

I need to put the four example $ ('.[class]').change functions into a loop. The D7codes array doesn't read in as a dynamic class changer (where I've put [class] in this comment). Also, do I need an overall change function so the loop executes each time?

Currently it works in long hand how I want it to, but I'm going to need to use this autosum throughout a project that other people will need to refer to, and it's going to get really messy.

This code looks for change (check box) in a class - I haven't included the python and html elements because it works correctly currently. There are four functions that need to be in a loop.

Apart from the class names in the D7codes array the only other two things that change within the functions are the numbers, ascending, after the 'question' and 'click' variables (0-4)

var question0 = 15.99;
var question1 = 20.99;
var question2 = 5.99;
var question3 = 2.99;

var total = 0

var click0 = false;
var click1 = false;
var click2 = false;
var click3 = false;


var click99 = false;

//this array is for the class names (currently the array isn't being used as I've elongated the code back out

var D7codes = [d7-r6,d7-r7,d7-r8,d7-r9]


//the four functions that should be in a loop

$ ('.d7-r6').change( function() {
  click0 = !click0; 
  if (!click99) {
    total += click0 ? question0 : -question0 
  } else { 
    totalOrig += click0 ? question0 : -question0 
  }
  var totalFloat = parseFloat(total).toFixed(2)
  $ ('.asum-total').text(totalFloat);
});

$ ('.d7-r7').change( function() {
  click1 = !click1; 
  if (!click99) {
    total += click1 ? question1 : -question1 
  } else { 
    totalOrig += click1 ? question1 : -question1 
  }
  var totalFloat = parseFloat(total).toFixed(2)
  $ ('.asum-total').text(totalFloat);
});

$ ('.d7-r8').change( function() {
  click2 = !click2; 
  if (!click99) {
    total += click2 ? question2 : -question2 
  } else { 
    totalOrig += click2 ? question2 : -question2 
  }
  var totalFloat = parseFloat(total).toFixed(2)
  $ ('.asum-total').text(totalFloat);
});

$ ('.d7-r9').change( function() {
  click3 = !click3; 
  if (!click99) {
    total += click3 ? question3 : -question3 
  } else { 
    totalOrig += click3 ? question3 : -question3 
  }
  var totalFloat = parseFloat(total).toFixed(2)
  $ ('.asum-total').text(totalFloat);
});

//This next function doesn't need to be in the loop but is referred to so I've //left it in for clarity


$ ('.d7-r99').change( function() {
  click99 = !click99; 
  if (click99) {
    totalOrig = total;
    total = 0;
  } else { 
    total = totalOrig; 
  }
  var totalFloat = parseFloat(total).toFixed(2)
  $ ('.asum-total').text(totalFloat);
});