my $row = 0;
my $column = 0;

for (my $i = 9; $i >= 0; $i--) 
{
$button{$i} = $mw->Button(-text    => "$i", 
                          -width   => '3', 
                          -height  => '1', 
                          -command => &numpress($i))
                   ->grid(-row     => $row,
                          -column  => $column);

$column++;
if($column > 2){$column = 0; $row++;}
}


MainLoop;