How to return sum of child process to parent process and add 100 elements of array by each process and use fork funtion to create process

This code creates an array of 1000 elements and it should be initialized which i have not done and create 10 child processes using fork function as i don’t know how to use fork function so i used simple variable to create processes and add 100 elements of each process and return it to parent process

#include<stdio.h>  
#include<unistd.h>
#include<sys/types.h>
#include<string.h>

int main()
{
    int pipeDes[2];
    pipe(pipeDes); // Create pipe
    int procs = 1; //self is first

    int tempIn[1000];
    while (fork() == 0) //at child and calculates sum of elements of 100 elements array by each process and return to parent process
    {
        ++procs;

        if (procs == 2) // 1st child process
        {

            int sum = 0;

            close(pipeDes[1]);

            for (int i = 0; i < 100; i++)
            {
                read(pipeDes[0], &tempIn[i], 4); // Read each integer and store in array of integers

                sum = sum + (int) tempIn[i]; // Add the integers and store in sum
            }

            close(pipeDes[0]); //close pipe
            return sum;
        }

        if (procs == 3) // 2nd child process 
        {

            int sum = 0;

            close(pipeDes[1]);

            for (int i = 100; i > 100 && i < 200; i++)
            {
                read(pipeDes[0], &tempIn[i], 4); // Read each integer and store in array of integers

                sum = sum + (int) tempIn[i]; // Add the integers and store in sum
            }

            close(pipeDes[0]); // close pipe

            return sum;
        }

        if (procs == 4) // 3rd child process
        {

            int sum = 0;

            close(pipeDes[1]);

            for (int i = 200; i > 200 && i < 300; i++)
            {
                read(pipeDes[0], &tempIn[i], 4); // Read each integer and store in array of integers

                sum = sum + (int) tempIn[i]; // Add the integers and store in sum
            }

            close(pipeDes[0]); // close pipe

            return sum;
        }

        if (procs == 5) // 4th child process 
        {

            int sum = 0;

            close(pipeDes[1]);

            for (int i = 300; i > 300 && i < 400; i++)
            {
                read(pipeDes[0], &tempIn[i], 4); // Read each integer and store in array of integers

                sum = sum + (int) tempIn[i]; // Add the integers and store in sum
            }

            close(pipeDes[0]); // close pipe

            return sum;
        }

        if (procs == 6) // 5th child process
        {

            int sum = 0;

            close(pipeDes[1]);

            for (int i = 400; i > 400 && i < 500; i++)
            {
                read(pipeDes[0], &tempIn[i], 4); // Read each integer and store in array of integers

                sum = sum + (int) tempIn[i]; // Add the integers and store in sum
            }

            close(pipeDes[0]); // close pipe

            return sum;
        }

        if (procs == 7) // 6th child process
        {

            int sum = 0;

            close(pipeDes[1]);

            for (int i = 500; i > 500 && i < 600; i++)
            {
                read(pipeDes[0], &tempIn[i], 4); // Read each integer and store in array of integers

                sum = sum + (int) tempIn[i]; // Add the integers and store in sum
            }

            close(pipeDes[0]); //close pipe

        }

        if (procs == 8) // 7th child process
        {

            int sum = 0;

            close(pipeDes[1]);

            for (int i = 600; i > 600 && i < 700; i++)
            {
                read(pipeDes[0], &tempIn[i], 4); // Read each integer and store in array of integers

                sum = sum + (int) tempIn[i]; // Add the integers and store in sum
            }

            close(pipeDes[0]); // close pipe

            return sum;
        }

        if (procs == 9) // 8th child process
        {

            int sum = 0;

            close(pipeDes[1]);

            for (int i = 700; i > 700 && i < 800; i++)
            {
                read(pipeDes[0], &tempIn[i], 4); // Read each integer and store in array of integers

                sum = sum + (int) tempIn[i]; // Add the integers and store in sum
            }

            close(pipeDes[0]); // close pipe

            return sum;
        }

        if (procs == 10) // 9th child process
        {

            int sum = 0;

            close(pipeDes[1]);
            for (int i = 800; i > 800 && i < 900; i++)
            {
                read(pipeDes[0], &tempIn[i], 4); // Read each integer and store in array of integers

                sum = sum + (int) tempIn[i]; // Add the integers and store in sum
            }

            close(pipeDes[0]); // close pipe

            return sum;
        }

        if (procs == 11) // 10th child process
        {

            int sum = 0;

            close(pipeDes[1]);

            for (int i = 900; i > 900 && i < 1000; i++)
            {
                read(pipeDes[0], &tempIn[i], 4); // Read each integer and store in array of integers

                sum = sum + (int) tempIn[i]; // Add the integers and store in sum
            }

            close(pipeDes[0]); // close pipe 

            return sum;
        }

        if (procs == 12)
            break;

    }

    return 0;
}
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