I am seeing these messages when I click memberlist or select threads. Please help!

Warning: Division by zero in /home/freebb/includes/functions.php on line 576

Warning: Division by zero in /home/freebb/includes/functions.php on line 583

Warning: Division by zero in /home/freebb/memberlist.php on line 308

Warning: Division by zero in /home/freebb/memberlist.php on line 308