If you've ever wondered about how Braille was created, when the skateboard first appeared, or why the time machine has yet to be invented, then you'll want to check out this book! 101 inventions are given two page histories/factoids, accompanied by a worksheet for readers to complete. For example, the entry for Roller Coaster gives a history of the invention, including steep icy hills built in Russia during the 1700s, where people would ride down on seats made of wood or ice. The accompanying worksheet asks readers to list their favorite roller coaster, how many times they've ridden it, the types and amounts of loops, and the consequences of riding. Readers will find recommendations with each entry for other inventions they may enjoy. The book includes items that have yet to be invented (a teleporter, terraforming, anti-aging pills, etc.) and "If Only" items, such as a Know-It-All Hat, a Language Decoder, and a Weather Machine. This is a great book for tweens and teens, and is fun for just browsing. A concern for libraries may be that the book encourages readers to write in it, cut pages out, and use stickers to mark inventions that have been fully researched.