Why not put your last two cases together?

$runningTotal += .5, return if $answer =~ /^[gk][0-5]$/;

# instead of
$runningTotal += .5, return if $answer =~ /^g[0-5]$/;
$runningTotal += .5, return if $answer =~ /^k[0-5]$/;
[download]

-- Hofmator