Unlocking a keypad combination lock is quick and easy:
On the outside, first press the "C" button or turn the knob, lever handle, or thumb turn as far as it will go. This will clear out any previous keypad entries.
Next, enter in the secret code.
Finally, turn the knob, lever handle, or thumb turn to retract the deadbolt/latchbolt.
On the inside, just push the panic bar. You don't need to enter the code.
Locking is even easier:
This is a latchbolt lock so it will latch and lock automatically whenever the door is closed.