The results of my study allow determining permissible limits of the average time of implementation of one operation and relative frequency of occurrence of errors while a pupil implements a sequence of simple uniform operations. All pupils who had not reached the limits could not learn mathematics without big problems. They could not work at lessons of full value and do homework themselves. Their knowledge and skills were very bad. In contrary, in those cases when it was possible to improve their elementary mental computational skills, they began to make progress.

If you want to know more about the implemented study, you can go to

You can find there a description of the study with some figures and diagrams, a test for diagnosis of elementary mental computational skills and a description of two effective ways for improvement of the skills:

1) The testing tables which are an effective means for training work. Their using lets to bring up quickly the elementary mental computational skills to the level exceeding the calculated permissible limits of the considered parameters.

2) The teaching computer program for improvement of elementary mental computational skills. It makes a diagnosis of a level of the skills; carries out the work on improvement of the skills; carries out control by a psycho-physical state of a pupil and by a level of permissible working load; allows controlling the results of working.