calculator.rb

def calculator(number_one, number_two, operation)
  # check which operator
  case operation
  when '+'
  # compute the right operation
    result = number_one + number_two
  when '-'
    result = number_one - number_two
  when '*'
    result = number_one * number_two
  when '/'
    result = number_one.fdiv(number_two)
  end
  return result
end

def checker_to_f(number)
  if number =~ /\d+(\.\d+)?/
  number = number.to_f
  else
    puts "#{number} is not a number"
    number = nil
  end
  return number
end