Add and format leading zero's in a string
<p>I want to show a number in my app, and to keep it pretty, display leading zeros to make the layout even. </p>

<p>For example </p>

<pre><code>000 500 / 500 000
001 000 / 500 000
100 350 / 500 000
</code></pre>

<p>I get the first number from an Int, and I want to format it into a string.
Is there a neat way to assure that a number is always six digits, and also get the range of the leading zeros to format them differently? </p>