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)

print "Here is a puzzle."

# -4391 = 35 + (74 - (180 * (50 / 2)))

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

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

c = 19
d = 7
e = 16
f = 20
g = 1984

print "(((19 + 7) * 16) / 20) - 1984 = ", subtract(divide(multiply(add(c, d), e), f), g)