title: Rational add/subtract method Java
body: <p>These are the current codes for my addition subtraction methods that work perfectly fine:</p>
  
  <pre><code>public static Rational sub(Rational r1, Rational r2){
      int a = r1.getNum();
      int b = r1.getDenom();
      int c = r2.getNum();
      int d = r2.getDenom();
  
      int numForNow = a*d - b*c;
      int denomForNow = b*d;
  
      Rational ratNum = new Rational (numForNow, denomForNow);
  
      return ratNum;
  
  public static Rational add(Rational r1, Rational r2){
      int numForNow = r1.getNum()*r2.getDenom() + r2.getNum() * r1.getDenom();
      int denomForNow = r1.getDenom() * r2.getDenom();
  
      Rational ratNum = new Rational (numForNow, denomForNow);
  
      return ratNum;
  }
  </code></pre>
  
  <p>So if I add two rationals like 1/3 and 4/6 I would get 18/18 (reduces to 1).
  However, I want to write these in a different way so that the program sees that 3 goes into 6 and would just print out 6/6. </p>
  
  <p><br><br>I know I would take the LCM for the denominator, which I understand. I don't understand how to make it so that the numerator would follow suit?
  <br><br>Also, I think there would need to be an if statement to determine whether or not to use the LCM or just continue using the code already there.</p>