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Declination is merely a number, but figuring it and understanding it the concept often resulted in a scout struggling with using a compass and enjoying orienteering. What do you mean, my compass doesn't point to the northpole? What do you mean it moves around? More often than not, the scout dismisses the whole idea of declination once he gets by this requirement in scouting. Afterall, a GPS unit does this type of thing for you ...
So to all those that tried to help others understand this simple little calculation, a letterbox has been placed; Declination.