Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
How does the terminal react when you try to enter numbers? does it beep, or show any overt sign of a reacting?
Try pressing ENTER before entering the number, see if that allows number entry. Other keys might also be tried - it could be a situation like trying to fill in an entry in a web form, when you haven't clicked on the entry box to place the cursor there first.