def add(a, b):
    print("ADDING %d + %d" % (a, b))
    return a + b

def subtract(a, b):
    print("SUBTRACTING %d - %d" % (a, b))
    return a - b

def multiply(a, b):
    print("MULTIPLYING %d * %d" % (a, b))
    return a * b

def divide(a, b):
    print("DIVIDING %d / %d" % (a, b))
    return a / b

print("Let's do some math with just functions!")
age = add(30, 5)


height = subtract(78, 4)
weight = multiply(90, 2)
iq = divide(100, 2)

print("Age: %d, Height: %d, Weight: %d, IQ: %d" % (age, height, weight, iq))


# A puzzle for the extra credit, type it in anyway.
print("Here is a puzzle.")

what = add(age, subtract(height, multiply(weight, divide(iq, 2))))

print("That becomes: ", what, "Can you do it by hand?")

Let's do some math with just functions!
ADDING 30 + 5
SUBTRACTING 78 - 4
MULTIPLYING 90 * 2
DIVIDING 100 / 2
Age: 35, Height: 74, Weight: 180, IQ: 50
Here is a puzzle.
DIVIDING 50 / 2
MULTIPLYING 180 * 25
SUBTRACTING 74 - 4500
ADDING 35 + -4426
That becomes:  -4391.0 Can you do it by hand?