title: Return value in multiples of 4
body: <p>I am having some difficulties with my code namely to do with multiples.</p>
  <p>Firstly, if <code>basket.length</code> is greater or equal to 4 (4, 8, 12, 16...) then I would like the following element to be displayed:</p>
  <pre><code>&lt;div class=&quot;alert alert-danger&quot; role=&quot;alert&quot; *ngIf=&quot;basket.length % 4 === 0&quot;&gt;
    You need to select at least {{ getNumberOfMuffins() }} muffins 
  &lt;/div&gt;
  </code></pre>
  <p>Secondly, if the value of <code>this.basket.length</code> is not or greater of equal to 4 (4, 8, 12, 16...), then round it up to the next multiple of 4. If it is a multiple of 4 then just return the number. For example:</p>
  <p>if <code>this.basket.length === 3</code>, then go up to 4
  if <code>this.basket.length === 5</code>, then go up to 8
  if <code>this.basket.length === 9</code>, then go up to 12</p>
  <pre><code>getNumberOfMuffins() {
    // do some stuff
    // return the rounded number of muffins required
  }
  </code></pre>