title: How to set precision of a float
body: <p>Can someone explain me how to choose the precision of a float with a C function?</p>
  
  <p>Examples:</p>
  
  <p><code>theFatFunction(0.666666666, 3)</code> returns 0.667</p>
  
  <p><code>theFatFunction(0.111111111, 3)</code> returns 0.111</p>