Try this
$('.rating .voteup').on('click', function () {
var up = $(this).closest('div').find('.up');
up.text(parseInt(up.text()) + 1);
return false;
});
$('.rating .votedown').on('click', function () {
var down = $(this).closest('div').find('.down');
down.text(parseInt(down.text()) + 1);
return false;
});