Abstract: The present invention relates to data manipulation and in particular incrementing, decrementing and comparing binary coded numbers, notably the manipulation of thermometer codes and the performance of arithmetic operations thereon. A method of processing data is provides which comprises receiving a series of data samples, each sample being represented as an N-bit thermometer code, wherein the most significant bit thereof represents the sign of the data sample value Y(n) and the remaining N?1 bits represent the magnitude of the data sample and executing a predetermined sequence of arithmetic operations directly on the series of N-bit thermometer code data samples to determine one of two values for each data sample, without any recoding of the thermometer code data samples.