The fourth book in the Life of Fred Upper Elementary/Middle School Series Life of Fred is a series of math books that break the old pattern of drill and kill. Instead of nothing but dry exposition and endless drill exercises, they contain fun stories about Fred Gauss, a child prodigy math genius. During his hilarious adventures, he encounters situations that call for solving math problems. Dr. Stanley Schmidt wrote these to make math come alive with humor, clear explanations, and silly illustrations that will make math a fun subject. Your children actually want to read these books. The stories carry on through the exercises, leading the student through them. Many of the books have a series of quizzes called Bridges every few chapters. Passing a quiz means the student is ready for the next chapter. Some books have all the problem solutions in them, while others have separate answer keys or companions. The textbooks are all hardbound, the answer keys are comb-bound.
I have found no better option for teaching higher math. Life of Fred goes so for beyond the basic formula approach, and teaches real-life application of advanced concepts. Even better, it's all taught through the very interesting and absolutely laugh-out-line story line of young Fred Gauss.
There was actually a lot more (very basic) biology than pre-algebra. The math was more of a side thing and was very basic pre-al at that. But as usual, a very fun book over all.