calculator

loop = true
while loop == true do
textutils.slowPrint("Welcome to EnderCalc Version 0.1!")
print("Type End to cancel the program")
print("Would you like to add, subtract, multiply, or divide?")
local operation = read()
if operation == "end" or "End" or "e" or "E" or "END" then
 loop = false
end
--------------------------------------------------
function nums()
print("Enter the first number to be operated on please: ")
local num1 = tonumber(read())
print("Enter the second number to be operated on please")
local num2 = tonumber(read())
end
--------------------------------------------------
if operation == "add" or "ADD" or "a" or "A" then
  nums()
  local result = num1 + num2
  print(result)
elseif operation == "subtract" or "Subtract" or "s" or "S" then
  nums()
  result = num1 - num2
  print(result)
elseif operation == "multiply" or "Multiply" or "m" or "M" then
  nums()
  result = num1 * num2
  print(result)
elseif operation == "divide" or "Divide" or "d" or "D" then
  nums()
  result = num1 / num2
  print(result)
else
  print("Try again")
end
end