Oki C3520 - Manual (Page 44)

Configuring your machine.... > 44
When a number is entered from the Ten Key pad, the
number currently displayed is cleared and the number just
entered is displayed as the first digit. When another
number is entered, the number in the first digit moves to
the next, and so on.
7. To confirm, press the Enter key.
Cancelling the IP address
To cancel the IP address, move the cursor to the first field and
then press the Left arrow key.