The examples provided by Mr. Schlenker take advantage of charge balancing whenever possible.  This only works if you have IONS as a part of the equation.  The total charge of all reactants must be the same as the total charge of all products.  This is often a quicker method of determining H¹⁺ and OH^1- than what is shown in the text book.

example #1 - neutral compounds (20)

example #2 - ionic (24)

example #3  - acidic solutions (28)

example #4  - basic solutions (27)