Multiple independent-gate field effect transistors (MIGFETs) have great potential for digital integrated circuits. In this work, we demonstrate that conventional binary adder architectures may benefit from the use of MIGFET devices. As case studies, we have designed ripple-carry adders (RCA) and parallel-prefix adders (PPA), where circuit area and performance optimizations are explored. Different versions of adders have been built using MIGFET and compared to adder topologies based on single-gate transistors.