This formula enables you to work out every major and minor key signature and is much quicker than constructing every tone and semitone. I also give some tips and techniques for remembering the order of sharps and flats.

In this video, at 22:30, I refer to my exam technique guide "How to Take ABRSM Theory Grades 1, 2 and 3" available in Paperback and eBook from Amazon (links below to UK and USA sites) and show how this formula is an invaluable exam tool.

https://www.amazon.co.uk/dp/B0756KRMLK
https://www.amazon.com/dp/B0756KRMLK