How can I write this equation.
Pretty much here is what I have
(float) $total = (float) $product_price * (float) $percentage;
return (float) $total;
If I understand correctly, you want to add the percentage (tax?) to the total. If the
$country_percentage is the integer '10', that would equate to '0.10'
($total * (1 + ($country_percentage / 100))
Which would be
($total * 1.10)