title: Method that calculates percentage change between 2 numbers returns wrong number
body: <p>So i have this method that calculates the percentage change of the 2 numbers.</p>
  <pre><code>public static double getChange(double start, double end) {
      return ((end - start) / start) * 100;
  }
  </code></pre>
  <p>This outputs 1.0000000000000009</p>
  <pre><code>getChange(1, 1.01)
  </code></pre>
  <p>And this outputs -0.990099009900991</p>
  <pre><code>getChange(1.01, 1)
  </code></pre>
  <p>But they  both output wrong specially the below one. The first one should be 1 and the second -1. Is something wrong in my math or is this just some wierd thing in java? And how would i fix it so it would return the right percentage change.</p>