Vote up down total max

Question

Hey tried to search for similar but guess my english fail me lol, well here is what i need help with, im trying to make a vote system with up/down vote and wanna show it like this

5.3/10

but have no idea how to make total "5.3" not go over 100% = 10 here is my code so far

<?php 

$Vote_up = 804;
$Vote_down = 942;
$total = $Vote_up + $Vote_down;
$result = 100;

echo number_format($total/$result,1,",",".") . "/10"; 

?>

result is 17,5/10

ps. new to php so be easy on me ^^

Answer 1

i am really bad at maths but i think this should be work

$Vote_up = 555;
$Vote_down = 555;
$total = $Vote_up + $Vote_down;

if( $total <= 0 ){
    $score = -11;
} else {
    $score = (($Vote_up / $total) + ($Vote_down / $total) * 10) * -1;
}
echo floor( $score + 11 ) . '/10';

if someone have a better solution, please i would like to know it - thanks!