Euler Project in Ruby - Problem 6

euler6.rb

def sum_of_squares upto
  a = 0
  (1..upto).each { |x| a += x**2 }
  a
end
 
def square_of_sum upto
  a = 0
  (1..upto).each { |x| a += x }
  a**2
end
 
puts square_of_sum(100) - sum_of_squares(100)