title: How to calculate total amount?
body: <p>I'm fairly new to C# so i'm having problems understanding calculations in C#.</p>
  
  <p>Firstly, my products that i want to sell, are in a tab page in a tabcontrol.
  A checkbox and numeric up down is used to indicate the quantity and whether or not to add to my shopping cart, which is in another tabpage. The adding of items to shopping cart is by a button. </p>
  
  <p>How do i write the codes where the quantity (numeric up down) * the price equals the total?
  I have to do this for several products.</p>
  
  <p>I still don't really understand float, decimal etc. So this is really a headache to me.</p>
  
  <p>Btw i'm doing this on windows form</p>