from multiprocessing import Process, Queue
from time import time


def task_handler(current_list, result_queue):
    total = 0
    for n in current_list:
        total += n
    result_queue.put(total)


def main():
    processes = []
    number_list = [x for x in range(1, 10000001)]
    result_queue = Queue()
    index = 0
    for _ in range(8):
        p = Process(target=task_handler, args=(number_list[index: index + 1250000], result_queue))
        index += 1250000
        processes.append(p)
        p.start()
    start = time()
    for p in processes:
        p.join()
    total = 0
    while not result_queue.empty():
        total += result_queue.get()
    print(total)
    end = time()
    print("Execution time: ", (end - start), 's', sep=' ')


if __name__ == "__main__":
    main()

50000005000000
Execution time:  0.184340238571167 s