ex21_2.rb

#!/usr/bin/env ruby

def add(a, b)
    puts "ADDING #{a} + #{b}"
    a + b
end

def subtract(a, b)
    puts "SUBTRACTING #{a} - #{b}"
    a - b
end

def multiply(a, b)
    puts "MULTIPLYING #{a} * #{b}"
    a * b
end

def divide(a, b)
    puts "DIVIDING #{a} / #{b}"
    a / b
end

puts "Let's do some math with just functions!"

age = add(30, 5)
height = subtract(78, 4)
weight = multiply(90, 2)
iq = divide(100, 2)

puts "Age: #{age}, Height: #{height}, Weight: #{weight}, IQ: #{iq}"

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

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

puts "That becomes: #{what} Can you do it by hand?"
puts

#Extra credit:
#Try to figure out the normal formula
#

puts "Extra credit:"
normal_formula = age + (height - (weight * (iq/2)))
puts "This is the result of the normal formula #{normal_formula}"
puts