Thread: Help with a grading program in C

so I am doing this assignment for homework and I got everything working except for 1 portion and I am pretty sure it's something obvious that I just can't see. the program needs to be able to take the grades you enter tell you how many are passing and also give you an error when it goes over 100 and then the program will stop once given a -1 input, these portions are working the part I am stuck on is it also needs to take all the numerical grades entered and tell you what percent are passing. The program keeps giving me an outlandish percentage when i enter the test case which i will put below. I am not the best math student so this could be a simple math calculation i'm missing. I would appreciate any nudge in the right direction. Thanks!

Test Case:
45
90
70
87
123
100
-1

Code:

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


main() {


	int grade = 0, sum = 0, pass = 0, percent, fail = 0;


	


	while (grade != -1) {
		printf("Enter a numeric grade (-1 to quit):");
		scanf_s("%i", &grade);


		if (grade >= 70 && grade <= 100)
			pass = pass + 1;




		if (grade > 100)
			printf("This is not a valid grade.\n");


		if (grade > 0)
			sum = sum + 1;


		if (grade < 70 || grade > 100)
			fail = fail + 1;
		}
printf("You entered %i passing grades.\n", pass);


percent = fail / sum * 100;
printf("%i%% of the valid grades entered are passing grades.\n", &percent);


	system("pause");
}