The article demonstrates, on the basis of arithmetic lessons with physically handicapped pupils, that individualised teaching methods can be considerably more effective with the aid of technology. The demand for extreme individualized instruction justified not only by psychological but also physical reasons, is attempted to be met in an important partial area, i.e., the acquisition of arithmetical skills by means of practice. Within the framework of a research project carried out on behalf of the Federal Minister of Labour, a device has been developed which takes into consideration the medical, special educational and technical viewpoints and helps to meet the practical requirements whilst taking into account the multidisciplinary problem complex. the device is an electronic trainer for mental arithmetic exercises which can be constructionally adapted to the pupil's physical deviation. It is programmed by the teacher in accordance with the different performance levels and is then a direct partner irrespective of the pupil's degree of disability.