You are completely correct -- except that most styles say to write 154 as "one hundred and fifty-four." (I personally omit the "and" but I've been told I'm wrong to do so.)
Other types of these "other types" of adjectives include "this" or "those" (they tell you which ones) or words that tell you how many when they are not numbers, like "a few" or "some."
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.