lua计算器不能正常工作

在我敲入+ - * 或 / 以外的任何字符时，它仍然会将所有的东西输出出来，只是最后会显示“无效”

print("+-*/?")
method = io.read()
if method == "+" or "-" or "*" or "/" then
  print("输入第一个数字")
  num1 = io.read()
  print("输入第二个数字")
  num2 = io.read()
elseif method ~= "+" or "-" or "*" or "/" then
  print("无效")
end

if method == "+" then
  plusnum = num1 + num2
  print(plusnum)
elseif method == "-" then
  minusnum = num1 - num2
  print(minusnum)
elseif method == "*" then
  timesnum = num1 * num2
  print(timesnum)
elseif method == "/" then
  percentnum = num1 / num2
  print(percentnum)
end