I have said it before, I think, but the SatNav on my car seems to have been designed by a masochist. I can only assume it is because he designed the interface for the world, but still....

In the UK, the most common way of selecting an address is using the postcode, which is something like NA1 7DG (no idea where that is.)

So: press a button to start entering the destination. This brings up a screen where entering a postcode is not an option, so you press another to get to the one which has several options, including entering the postcode. So you press that one.
You are then offered a keyboard with letters. You enter NA and then there is nowhere else to go. You press another button to bring up the choice of things you could now enter. There are always 2: the letters, where you already are, and numbers. So you select numbers. You can now enter the 1 and the 7 (a space may be needed in rare cases, but that is on the number keyboard, fortunately). Now you need the letters again. The satnav know you can't enter another number, but no, you have to bring the menu up again, be offered staying with numbers, or go back to letters. Select letters and you can finally put in the DG. Finished at last ... no, you are now offered the list of all the places with that postcode, which is always one, and you have to select it.