Abstract: An apparatus for the exact weighing of materials, especially fruit and vegetables, in lots of mixed-size pieces feeds a plurality of pieces to a plurality of scales, carries out the weighing of one or more pieces on single scales, calculates the sum of successive groups of weights read from differently selected scales, and the difference between the wanted draft and each of said sums in order to select the group of weights and hence of scales carrying pieces for a total weight differing from the wanted draft to a predetermined allowed extent, and operates the unloading of the pieces from the selected scales.