Base: Number Bases: Introduction / Binary Numbers - Purplemath Number Bases Number Bases http://www.purplemath.com/modules/numbbase.htm Number Bases "Purple Math": Bases numéricas [em inglês] purplemath.com purplemath.com Number Bases http://www.purplemat...es/numbbase.htm Number Bases Lesson PurpleMath.com; Number Bases purplemath.com purplemath.com web page http://www.purplemath.com/modules/numbbase.htm