ex21.py

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 extra credite
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?"