As a basic cell of arithmetic circuits, a one-bit full adder and a counter are usually used. Minimizing power consumption of these components is a key issue for low-power circuit design. This paper proposes a new design method, in which basic cells are selected from a set of circuits with different structures (symmetrical and asymmetrical) and connections to their terminals are exchanged, according to input-patterns to minimize power consumption. Experimental results for a parallel multiplier demonstrate average 30% power reduction.