title: jQuery subtracting numbers is creating more decimal place that assigned
body: <p>Firstly, I just want to say i'm new to JS/JQUERY so forgive me if my terminology or code is all over the place.</p>
  
  <p>i'm writing this little thingy <a href="http://codepen.io/mike-grifin/pen/pjRrBb" rel="nofollow">http://codepen.io/mike-grifin/pen/pjRrBb</a> but if you click the 170.99 box and then keep tapping any of the other boxes the total goes to -34041.979999999996 i dont know why it has so many decimal places when i'm using .toFixed(2);</p>
  
  <p>See JQUERY below:</p>
  
  <pre><code>$(window).ready(function(){
  
  
  function getCash () {
  return parseFloat (prompt('How much cash you got?'));
  }
  
  var customerName = "Mike";//prompt('What is your name?');
  var cash = (500).toFixed(2); //getCash().toFixed(2);
  while (isNaN(cash)) {
  cash = getCash();
  }
  
  $('.customer-name').append(customerName);
  $('.cash').append(cash);
  
  if (cash &lt;= 0 ) {
  $('.result').append("Not enough cash bro!");
  }
  else if (cash &gt; 1000) {
  $('.result').append("woah! Big Spender, Maybe this shop isn't for you.");
   }
  
  else {
  $('.result').append("Welcome, shop til you drop");
  setTimeout(function(){
  $('.shop').removeClass('is-not-showing');
  }, 1000);
  }
  
  $('.item').on('click', function(){
  var purchase = ($(this).text());
  $('.cash').text(cash -= purchase).toFixed(2);
  
  });
  
  });
  </code></pre>
  
  <p>Thank you in advance if you can help out at all :)</p>