还请帮忙,此程序有错误
module Adder
def add(operand_one,operand_two)
return operand_one+operand_two
end
end
module Subtracter
def subtract(operand_one,operand_two)
return operand_one-operand_two
end
end
class Calulator
include Adder
include Subtracter
end
calculator=Calculator.new()
puts "5+3="+calculator.add(5,3).to_s
puts "5-3="+calculator.subtract(5,3).to_s