Two possible forms of numerical truth-table look-up processors using content-addressable optical holographic memories are presented. Application of these processors to performing numerical calculations in direct binary and in binary-coded residue number systems is discussed. Specific examples of the number of input and output bits required and the number of truth-table combinations holographically recorded for computation in both numerical systems are given. Truth-table look-up processing using binary-coded residue is shown to require the recording of dramatically fewer reference patterns than direct binary.