Программа проверки знаний таблицы умножения - C (СИ)

#include <stdio.h>
#include <stdlib.h>
 
static const int questions[][2] = {
    {2, 7}, {3, 7}, {5, 4}, {5, 7}, {3, 4},
    {8, 3}, {6, 6}, {5, 5}, {7, 7}, {3, 9}
};
 
#define SIZE (sizeof questions / sizeof *questions)
 
int main(void)
{
    size_t number, attempts;
    
    for(number = attempts = 0; number < SIZE && attempts < 10; ++attempts)
    {
        const int *question = questions[number];
        int answer;
            
        printf("%02zd) %d * %d = ", number + 1, question[0], question[1]);
        fflush(stdout);
        
        scanf("%d", &answer);
 
        if(answer == question[0] * question[1])
        {
            puts("Correct!");
            
            ++number;
        }
        else
            puts("Try once more");
    }
 
    printf("Questions answered: %zd; Total # of attempts: %zd; %% of correct answers: %.0f%%\n",
           number, attempts, (double) number / attempts * 100);
    
    exit(EXIT_SUCCESS);
}