Consider the program:

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

int main()
{
    int* ptr; //declaration of integer pointer
    int limit; //to store array limit
    int i; //loop counter
    int sum; //to store sum of all elements

    printf("Enter limit of the array: ");
    scanf("%d", &limit);

    //declare memory dynamically
    ptr = (int*)malloc(limit * sizeof(int));

    //read array elements
    for (i = 0; i < limit; i++) {
        printf("Enter element %02d: ", i + 1);
        scanf("%d", (ptr + i));
    }

    //print array elements
    printf("\nEntered array elements are:\n");
    for (i = 0; i < limit; i++) {
        printf("%d\n", *(ptr + i));
    }

    //calculate sum of all elements
    sum = 0; //assign 0 to replace garbage value
    for (i = 0; i < limit; i++) {
        sum += *(ptr + i);
    }
    printf("Sum of array elements is: %d\n", sum);

    //free memory
    free(ptr); //hey, don't forget to free dynamically allocated memory.

    return 0;
}

Output:

Enter limit of the array: 5
Enter element 01: 100
Enter element 02: 200
Enter element 03: 300
Enter element 04: 400
Enter element 05: 500

Entered array elements are:
100
200
300
400
500
Sum of array elements is: 1500