How to Change the World with a Ball of String is an easily browsable volume that covers scientific as well as historical information. Its organising idea is the arbitrariness of important discoveries and events, and introduces many key world events by drawing attention to their randomness. Headings such as "Discover a Continent ... by going the wrong way" and "Fight a War ... by sitting still" will entice children to read about Columbus's discovery of the Americas and the lack of movement in the Western Front of WWI.
Overall, this volumes is a great example of enticing and intriguing non-fiction for children which capitalises on kids' natural curiosity. It clearly starts from an assumption that children want to find out about things, rather than working from a list of what kids 'should' know. It's not a comprehensive reference book, but a 'dip-in' type one - although none of us has managed to dip in without reading longer than originally intended. What more can you ask?