Computers are playing an increasing role in education. Write a program that will help an elementry school student learn multiplication. Use the rand to produce two positive one-digit integers. it should then type a question such as:

How much is 6 times 7?

The student then types the answer. Your program checks the answer. If it is correct, print "Very good!", and then ask another multiplication question. If the answer is wrong, print "No, Please try again." and then let the student try the same question again repeatedly untill the student finally gets it right.

Exercise No. 3.36

The use of computers in education is reffered to as computer-assisted instruction ( CAI ). One problem that developes in CAI environment is student fatigue. This can be eliminated by varying the computer's dialogue to hold the student's attention. Modify the program of Exercise 3.35 so the various comments are printed for each correct answer and each incorrect answer as follows:

Responce to a correct answer

Very Good


Nice Work!

Keep up the good work!

Responce to an incorrect answer

No, please try again.

Wrong. Try once more.

Don't give up!

No. Keep trying.

Use the random number generator to choose a number from 1 to 4 to select an appropriate responceto each answer. Use a switch structure to issue the responce.

Exercise No. 3.37

More sophisticated computer-aided instruction systems moniter the student's perfomance over a period of time. The decision to begin a new topic is often based on the student's success with previous topics. Modify the program of Execise 3.36 to count the number of correct and incorrect responces typedby the student. after the student type the 10 answers, your program should calculate the percentage of correct responces. If the percentage is lower than 75 percent, your program should print, "Please ask your instructure for extra help" and then terminate.