(Computer-Assisted Instruction) The use of computers in education is referred to as com- puter-assisted instruction (CAI). Write a program that will help an elementary school student learn multiplication. Use the rand function to produce two positive one-digit integers. The program should then prompt the user with a question, such as How much is 6 times 7? The student then inputs the answer.

Question

Next, the program checks the student’s answer. If it’s correct, display the message "Very good!" and ask another multiplication question. If the answer is wrong, display the message "No. Please try again." and let the student try the same question repeatedly until the student finally gets it right. A separate function should be used to generate each new ques- tion. This function should be called once when the application begins execution and each time the user answers the question correctly.

What will be an ideal response?

Answer 1

```
// Help user practice multiplication.
#include
#include
#include
using namespace std;

int generateProblem(); // function prototype

int main()
{
int response = 0; // user response for product

srand( time( 0 ) ); // seed random number generator

// loop until sentinel value read from user
while ( response != -1 )
{
int answer = generateProblem(); // get product
cin >> response; // read user's guess

// loop until sentinel value or correct response
while ( response != -1 && response != answer )
{
cout << "No. Please try again." << endl << "? ";
cin >> response;
} // end while

// correct response
if ( response == answer )
cout << "Very good!" << endl << endl;
} // end while

cout << "That's all for now. Bye." << endl;
} // end main

// generates new product and displays prompt
int generateProblem()
{
int x = rand() % 10; // generate 1-digit random number
int y = rand() % 10; // generate 1-digit random number

cout << "How much is " << x << " times " << y << " (-1 to End)\n? ";

return x * y; // return product
```