Actual numbers -- whether they are BigDecmials, ints, longs, floats, bytes, or what-have-you --
never include leading zeros. They have no particular format at all: they represent an abstract mathematical concept. If you want to display leading zeros, you have to provide them yourself.
(Note that in
Java, if you write an integer literal with a leading 0, it's assumed to be a number in octal (base 8!))