<?php
  function show($x, $y) {
    print "<tr><td>" . $x . "<td>" . ($x+$y-$x);
  }

  print "<table border>";
  print "<tr><td>X<td>X+1000-X";

  show(1e9, 1000);
  show(1e18, 1000);
  show(1e27, 1000);

  print "</table>";  
?>