# our function that sums 3 numbers and displays the result
def sum_of_3(n1, n2, n3):
    result = n1 + n2 + n3
    print '%d + %d + %d = %d.' % (n1, n2, n3, result)


# calling the function 3 times.
sum_of_3(3, 9, 100)
sum_of_3(1, 1, -1)
sum_of_3(3.2, 2, 7.9)