Modern society is dominated by measurements. Many, if not most, important decisions are based on numbers coming from some kind of measurement. Frequently these measurements are used for ranking: modern society is obsessed with finding the best. Whether the measurements are relevant to the issue or the numbers make any sense is sometimes secondary. Ways have been devised to measure even intangibles, such as intelligence and love.
Henshaw's book is about the relationship between knowledge and measurement, "about what we measure, why we measure, and how we measure," as he says in the preface. It is also about how measurement can be and has been misused and abused. Henshaw admits that he is optimistic about the future of measurement. At some places he argues that measurement can induce improvement and progress, even if the measurement itself is questionable or actually irrelevant.
The book is well written, entertaining, and informative. But it is not a math book; it contains almost no math. However, it is certainly useful for improving math literacy, or what Paulos calls "numeracy". In this sense, Henshaw's book is close in spirit, if not form, to Huff's classic How to Lie with Statistics . Those who teach math will probably profit from reading it.
Luiz Henrique de Figueiredo is a researcher at IMPA in Rio de Janeiro, Brazil. His main interests are numerical methods in computer graphics, but he remains an algebraist at heart. He is also one of the designers of the Lua language.