for( my $i = 1; $i < 1000000000; $i *= 10 ) {
    my $bf = Math::BigFloat->new( $i );
    my $xpect = 
       ($bf > 1 ? '3' x (scalar($bf->length) - 1) : 0)
       . ".33";
    is $bf->bdiv(3)->bfround(-2), $xpect, $i . ' / 3 = ' . $xpect;
}