1. Get the errata list for the book. The RF math section had problems.
2. Even with the errata list applied, I find the RF math section confusing.
3. Grasp that decibel notation is a relatively simple way of multiplying (gain) and dividing (loss) huge and tiny numbers by adding and subtracting their exponents. It was invented for telephone technicians, not rocket scientists.
4. Converting between normal notation and decibel notation can be a challenge but once all factors are in decibel notation the product is found by adding the typically one and two digit decibel numbers.
5. The shorthand rules of 10s and 3s will lead you to the correct exam answer every time. Memorize these rules.
I hope this helps. Thanks. /criss