title: Recognizing when to use the modulus operator
body: <p>I know the <a href="http://en.wikipedia.org/wiki/Modulo_operation" rel="noreferrer">modulus</a> (%) operator calculates the remainder of a division. How can I identify a situation where I would need to use the modulus operator?</p>
  
  <p>I know I can use the modulus operator to see whether a number is even or odd and prime or composite, but that's about it. I don't often think in terms of remainders. I'm sure the modulus operator is useful, and I would like to learn to take advantage of it. </p>
  
  <p>I just have problems identifying where the modulus operator is applicable. In various programming situations, it is difficult for me to see a problem and realize "Hey! The remainder of division would work here!".</p>