Methods and apparatus for converting a radix 2 multiplier to respective groups of radix 4 encoded bits representing numbers of the group consisting of −2, −1, 0, 1, 2, wherein the set of encoded bits includes: a first bit that is true when the associated number is 2, a second bit that is true when the associated number is −2, a third bit that is true when the associated number is either negative or zero, and a fourth bit that is true when the associated number has an absolute value of 1.