Thread: Math Quiz program

I am programming a math quiz program for the college assignment below are a part of my code, the question is if user key in a char for the answer the program goes wrong, how to detect if the user keyed in char so i can send a message to user and say "Please enter a digit"

Code:

do    {
        no1 = rand() % 50 + 1;
        no2 = rand() % 50 + 1;
        pcAns = no1 + no2;


        printf("%d + %d = ", no1, no2);
        scanf("%d", &userAns);
         
        if (pcAns == userAns)
        {
            printf("Congratulation, your have entered the correct answer!!\n");
            mark = mark + 10;
        }
        else
            printf("Sorry the correct answer is %d \n", pcAns);


        count++;
    } while (count <= 10);