One way to simplify a number is to find a nearby one which is easier to remember .
Different people find different things easy to remember.
You just try on possibilities until you find one which is both easy enough and close enough. It usually takes a couple of tries, and sometimes it doesn't work. Finding numbers you can remember is important when you are creating your own landmarks . A View from the Back of the Envelope Comments encouraged. In need of overhaul, integration with landmarks.