Controlling imput text and animations

i am trying to control the animations for this banner. the idea is for someone to imput a number into the text field, then have the x come up on top of the number. but, if no one imputs a number into the text field, a number will automatically come up, then the x.

how can i control it so when someone imputs a number, my automatic number animation does not appear?

many thanks in advance!