Hey, I'm making a little program that will talk to you using fixed sentences etc., and I want to make it able to do math.

How would I be able to check if a string contains

+ - * /

and also contains numbers?

and then furthermore, once I have that, how would I be able to make it loop so I can also use questions such as

7 + 7 / 14

and it would give me the correct answer?

Thanks everyone