（1）电脑随机出10道题，每题10分，程序结束时显示学生得分；

（2）确保算式没有超出1~2年级的水平，只允许进行50以内的加减法，不允许两数之和或之差超出0~50的范围，负数更是不允许的；

（3）每道题学生有三次机会输入答案，当学生输入错误答案时，提醒学生重新输入，如果三次机会结束则输出正确答案；

（4）对于每道题，学生第一次输入正确答案得10分，第二次输入正确答案得7分，第三次输入正确答案得5分，否则不得分；

（5）总成绩90以上显示“SMART”, 80-90显示“GOOD”， 70-80显示“OK”, 60-70显示“PASS”，60以下“TRY AGAIN”。

-(1) Computer randomly out of 10 questions, each question 10 points, showing students score at the end of the program　(2) ensure that the formula does not exceed the level of grades 1-2, allowing only addition and subtraction within 50, the two numbers are not allowed poor or exceeds the sum of the range 0 to 50, and a negative number is not allowed　(3) Each question students have three chances to enter the answer, when students enter the wrong answer, remind students to re-enter, if three chances to end output The correct answer　(4) For each question, the students first enter the correct answer was 10 points, the second to enter the correct answer to 7 points, the third time to enter the correct answer is 5 points, otherwise no points　(5) total 90 results shown above " SMART" , 80-90 Show " GOOD" , 70-80 display " OK" , 60-70 display " PASS" , 60 the following " TRY AGAIN" .