I really don't see why everyone is trying to make this hard. Just tune the frequency you are told to go to. I don't bother even writing it down. So long as your radio has a use/standby frequency, as soon as you hear the new frequency tune it into standby (or com 2 if you wish), then repeat it back. Easy peasy. There is no reason to attempt to predict what frequency or sector you will be contacting. Keep It Simple Stupid!