C Program to calculate sum of 5 subjects and find percentage

#include<stdio.h>
#include<conio.h>

void main()
{
int s1,s2,s3,s4,s5,sum,total=500;
float per;

clrscr();

printf("Enter marks of 5 subjects : ");
scanf("%d%d%d%d%d",&s1,&s2,&s3,&s4,&s5);

sum = s1 + s2 + s3 + s4 + s5;

printf("Sum : %d",sum);

per = (sum * 100) / total;

printf("Percentage : %f",per);
getch();
}

Output :

Enter marks of 5 subjects : 80 70 90 80 80
Sum : 400
Percentage : 80.00