approx(dsin(30))
    approx(dcos(30))

##</code><code>##

    approx($num, 7);  # will return 0.5 for 0.500000001 but 0.50000001 if
                      # that is passed as it only has 6 zeros.

##</code><code>##

sub approx {
    my ( $num, $dp ) = @_;
    $dp ||= 6;
    if ( $num =~ m/\d*\.(\d*?)(9{$dp,})\d*/ ) {
        my $exp = 10** (length $1 + length $2);
      return int(($num * $exp) +1 )/$exp;

    }
    elsif ( $num =~ m/\d*\.(\d*?)(0{$dp,})\d*/ ) {
        my $exp = 10** (length $1 + length $2);
      return int($num * $exp)/$exp;
    }
    else {
        return $num;
    }
}