screencast 17

gistfile1.txt

#screen cast 17


 class Calculator
   include Math

   def add(num1, num2)
     num1 + num2
   end

   def multiply(num1, num2)
     num1 * num2
   end

   def divide(num1, num2)
     num1 / num2
   end

   def subtract(num1, num2)
     num1 - num2
   end

   def circumference_of_a_circle(radius)
     @c = 2 * PI * radius
   end

   def what_is_the_radus(input)
     circumference_of_a_circle(input)
   end

   def display_answer
     "The circumference of the circle is #{@c.round(3)}"
   end

 end
 calc = Calculator.new
 p calc.add(2, 4)
 p calc.multiply(4, 4)
 p calc.divide(10, 5)
 p calc.subtract(50, 100)
 print "Enter a radius: "
 calc.what_is_the_radus(gets.chomp.to_i)
 p calc.display_answer

I love the circumference method - I think you're the first to come up with that!