title: Looking for good substitute for calculating percentage employing integer math
body: <p>I am a hobbyist programming for an embedded application.  The application requires speed.  I would like to determine whether or not a certain variable (call it "X") has passed a certain percentage (call it "Y") of another variable (call it "Z").</p>
  
  <p>X, Y, and Z can all change at runtime.  Since I need speed I would like to do this using integer math as opposed to float, which incurs a speed penalty.</p>
  
  <p>Are there any tricks for doing this?  I am a self trained programmer so please excuse me if this is a well known problem with a well known solution.</p>
  
  <p>Thank you!</p>