Shopping cart error: Warning: Division by zero

Avg Bid (USD)
Project Budget (USD)
$30 - $250

Project Description:
My son's website is a storefront that uses a premium wordpress theme I have purchased. Both my host and the theme creator say the problem is not theirs. I am receiving the error message below when anyone tries to checkout or view their shopping cart on my site.

Warning: Division by zero in /home/saucyspi/public_html/wp-content/themes/mk4/pg/paypal/gateway.php on line 154

That line of code says:

$prodslistamount = $prodslistamount/$prodslistquantity;

Not really sure why it's trying to divide here. Need some help squaring this away so his customers can order.

Skills required:
AJAX, C Programming, C# Programming, C++ Programming, PHP
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