checking function doesn't work

Question

I'm trying to figure out what's wrong with my checkQuestion function. I don't know why but sometimes it won't check certain questions or completely skip them. I created a function createQuestion and I called checkQuestion in createQuestion so I don't know if that what's causing everything to mess up. Any help would be appreciated and I just need some clues as to whats wrong. I posted the link to the program if you want to run it.

https://repl.it/MQsD/142

#include <stdio.h> 
#include <stdlib.h> 
#include <time.h>

  int main(void) {

    srand(time(NULL));
    printf("Math quiz. \n");
    printf("This is level 1. There are a total of 10 questions. \n\n");

    createQuestion();
    checkQuestion();

  }

//Functions 

int integers(void) {

  int digit;
  digit = rand() % 10;

  return digit;

}

char operations(void) {

  int digit;
  digit = rand() % 4;

  if (digit == 0) {

    return '+';

  } else if (digit == 1) {

    return '-';

  } else if (digit == 2) {

    return '*';

  } else if (digit == 3) {

    return '/';
  }

}

int createQuestion(void) {

  int i;
  int count = 0;
  int answer;
  int sum;

  for (i = 1; i <= 10; i++) {

    count++;
    printf("%d)%d", count, integers());
    printf("%c", operations());
    printf("%d", integers());
    printf("=");
    scanf("%f", & answer);
    checkQuestion(integers(), integers(), operations(), answer);

  }
}

void checkQuestion(float a, float b, float c, char d) { //a integer b integer c answer //d operator

  int answer1;
  int answer2;
  int answer3;
  int answer4;

  if (operations() == '+') {

    answer1 == a + b;
    answer1 == c;
    if (answer1 == c) {

      return messagesGood();

    } else {

      return messagesBad();

    }

  } else if (operations() == '-') {

    answer2 = a - b;

    if (answer2 == c) {

      return messagesGood();

    } else {

      return messagesBad();

    }

  } else if (operations() == '*') {

    answer3 = a * b;

    if (answer3 == c) {

      return messagesGood();

    } else {

      return messagesBad();

    }

  } else if (operations() == '/') {

    answer4 = a * b;

    if (answer4 == c) {

      return messagesGood();

    } else {

      return messagesBad();

    }
  }

}

void messagesGood(void) {

  int digit;
  digit = rand() % 4;

  switch (digit) {

  case 0:
    printf("Very good! \n");
    break;

  case 1:
    printf("Excellent! \n");
    break;

  case 2:
    printf("Nice Work! \n");
    break;

  case 3:
    printf("Keep up the good work! \n");
    break;
  }
}

void messagesBad(void) {

  int digit;
  digit = rand() % 4;

  switch (digit) {

  case 0:
    printf("No. Please try again. \n");
    break;

  case 1:
    printf("Wrong. Try once more. \n");
    break;

  case 2:
    printf("Don’t give up! \n");
    break;

  case 3:
    printf("No. Keep trying. \n");
    break;
  }
}

Answer 1

One weird thing is, you have a function that returns a char:

**char** operations(void){
  etc...
}

then you put it in a function that expects a float:

checkQuestion(integers(), integers(), **operations()**, answer);
void checkQuestion(float a, float b, **float c**, char d)

Answer 2

Every time you call operations, you could get a different result. You need to compare against d in your conditions, not against operator. You have a similar issue in createQuestion, where what is passed to checkQuestion is probably not what was shown to the user.

For example:

if (d == '+') {
  // ...
}