This was a really fun book.  It can be read in multiple ways.  When one needs a quick fun story, they can read the tale of the butterfly looking for the largest number.  When they need to know about big numbers, there are info bits about that, and there are info bits about other things of note such as life of a butterfly, or volts of electricity in a lightbulb.  Overall, this book works on many levels that kids will find fun.