sub to_three_sig_digits {
    my $val = shift;
    if ($val =~ /^(0\.0*)(\d+)$/) {
        my $pre = $1;
        my $app = $2;
        return $val if length($app) <= 3;

        my $digits = substr($app, 0, 3);
        my $fourth = substr($app, 3, 1);
        $digits += 1 if $fourth >= 5;
        $val = $pre . $digits;
    } elsif ($val > 1) {
        $val = sprintf("%.2f", $val);
    } 
    return $val;
}