This paper presents a hardware technique to reduce of static and dynamic power consumption in FUs. This approach entails substituting some of the power-hungry adders of a 64-bit superscalar processor, by others with lower power-consumption, and modifying the slot protocol in order to issue as much instructions as possible to those low power consumption units incurring marginal performance penalties. Our proposal saves between a 2% and a 45% of power-performance in FUs and between a 16% and a 65% of power-consumption in adders.