Non-binary methods of computing utilizing a digital multistate phase change material. Addition, subtraction, multiplication, and division are accomplished with the controlled application of energy to a phase change material. In one embodiment, energy in an amount insufficient to set the reset state of a phase change material is provided to store one or more numbers and further energy characteristic of the performance of a mathematical operation is provided to effect a computation. The set energy of the reset state of a phase change material provides an interval of energy that may be used to define programming states along the high resistance portion of the electrical resistance response curve of a phase change material. By sub-dividing this interval of energy, a plurality of programming states can be defined which are distinguishable in energy relative to the reset state. Numerical values can be assigned to the programming states and computations in non-binary arithmetic bases can be completed by providing energy to effect controlled transformations between programming states.