PHP Warning Division by zero

Hello,

I get a error in my errorlog

PHP Warning: Division by zero in /home/hposkamn/public_html/wp-content/themes/autoportal/footer.php on line 23

I have look at the code on line 21 to 26:

<style>
@media only screen and (min-width:801px) {
footer .widget { width: <?php echo (102-2*$cnt)/$cnt; ?>%; }
#<?php echo $total_widgets['smt_footer_sidebar'][$cnt-1]; ?> { margin-right:0; }
}
</style>

Can you help me get the error out please?

Thanks Henk