An assembly includes a handheld power tool. The handheld power tool comprises a housing, a drive shaft mounted at the housing via a bearing, a drive unit to drive the drive shaft, handles which are fixedly attached to the housing, a fastening device to fasten a roughing disk to the drive shaft, a first sensor to measure a power consumption value or an acceleration sensor to measure positional change information, an evaluating unit to evaluate the power consumption value sensed or the positional change information produced so as to produce an evaluation result, and an outputting device to output the evaluation result.