Hey @Nashaat. Welcome to the Typeform Community! 🥳
Actually, the number question accepts up to 15 digits. =) Are you facing any issues when trying to fill out the form with more than 9 digits?
I'm trying to think of a workaround I could suggest and here is what I thought: is there any "common number" to all the employee's cards? For example, if the first number is always "0". If that's the case, then you can add a description that the 1st number is not necessary, and they can type from the 2nd, and so on. Do you believe something like this would work? Since it's only one number that would be missing, this alternative came to my mind.
Another option would be using the Short Text question, as you mentioned. You won't be able to guarantee they are typing numbers but you could add a description reinforcing this is only for numbers, if that helps. :)