Design: two integer addition trainers design requirements are as follows:
1, two integer addition operation, including operation must also be the result of the double digits; 2, the title of the controllable (according to the number of input data to determine the specific) 3, in practice can interrupt at any time, and to statistics result; 4, in the process of practice can statistical result (right and wrong)
5, if the answer to the input error, allowed to re-enter the answer many times (frequency can be set according to the need);
6, there are many kinds of evaluation methods for right or wrong; Switch structure integrated with 7, the practice process as a result, written to a file (10) for example exam. TXT 8, can be after the end of the practice of statistical final grade (right, to input error), 9, using a thread control, each time 1 minute to the king, (if there is no result after 1 minute, it is wrong to think)