Abstract: Arithmetic unit having a set of multipliers and adders receives initial data in the form of both digital operands and analog signals. Stochastic multipliers and adders carry out multiplication and addition. The initial data are converted to pseudorandom sequences to perform arithmetical operations of multiplication and addition. The arithmetic unit includes an n-bit pseudorandom numbers generator (12) that generates M-sequences with the period of N=2n−1 time slots. The M-sequences are used in two logic units (14, 16) that generate pseudorandom sequences with a given probability of occurrence of 1's. The digital operands are converted to pseudorandom sequences by data-to-sequence converters (54) that receive n-bit operand and pseudorandom sequences with a given probability of occurrence of 1's from one of the logic units.