Ready to learn? This book is full of learning!! Intersperced with the 101 "things" are "Hands On," "Brief Bio," and "Fun Fact" tidbits. The "Hands On" are ways to prove to yourself the principle being discussed on that page. The "Brief Bio" spots are brief biographies of scientists who either discovered or used some of the principles in the 101 things. And the "Fun Fact" tidbits are...well, fun! Interesting facts that not everyone knows. This book is written at the middle school reading level but is interesting enough to keep even college professors reading it.