title: How to add zeros to the left of a number
body: <p>I have a piece of code for converting a Decimal number into base 3</p>
  
  <pre><code>$number = 10; // For Example
  $from_base = 10;
  $to_base = 3;
  $base_three = base_convert ( $number , $from_base ,  $to_base );
  echo $base_three;
  </code></pre>
  
  <p>So the number that it echos is 101 and it has 3 digits.
  but I what it to echos is 000101 so that it has 6 digits.
  Converting Decimal into base 3 with always 6 digits even though it has only 3 or 4 useful digits, is my goal! how can I solve it ?</p>