In one example in accordance with the present disclosure a device is described. The device includes a cross-bar array of memristive elements. Each memristive element has a conductance value. The device also includes a column of offset elements. An offset element is coupled to a row of memristive elements and has a conductance value. The device also includes a number of accumulation elements. An accumulation element is coupled to a column of memristive elements. The accumulation element collects an intermediate output from the column and subtracts from the intermediate output an output from the column of offset elements.