A method is introduced for finding non-linear functions digitally. The design is based on voltage-to-frequency conversion (VFC) and decimal rate multiplication (DRM). A DC signal is applied to the VFC and analogue comparator, producing a digital number proportional to the square of the input voltage. For the second half-period, this digital number is applied together with the VFC output clock frequency to the DRM, producing a digital number proportional to the cubic and fourth powers of the input DC signal. Any of the three digital numbers can be selected and displayed.