The ARRL Published a great document that contains all of the basics of radio related mathematics to take you from Technician all the way to Extra class licensing.

You can also download the below PDF here: Book Supplemental Files/23rd Edition/Radio Mathematics.pdf


2018 Radio Suppliment

An even more comprehensive math reference for Amateur radio is the Supplemental Mathematics available below.

Download: Supplemental Files/2018 Edition/Radio Supplement.pdf