Rating System ( Math )

[the-dream]

Ok i have a website and i has a page where people can submit a rating:
1 2 3 4 5 6 7 8 9 10

It uses this calculation:

PHP Code:

$vote = $uservote + $row_RSVoteOnGame['userscore'] / 100 * $row_RSVoteOnGame['uservotes'];
    $vote = round($vote, '1');
    $votes = $row_RSVoteOnGame['uservotes'] + 1; 


But this doesen't give me and accurate out of 10 calc, could someone please show me an accurate way of doing this!