What the numbers really mean

Tim Harford hosts a programme on Radio 4 called More or Less which looks at the numbers in the news and helps listeners understand their importance and also any inaccurate conclusions which have been drawn from them. I have been a listener of this show for years and it has helped me to think harder about numbers which I hear or read and to examine more carefully what they might really show rather than what I am told that they mean. This book, How to Make the World Add Up, is fascinating even for someone like myself who is not confident in the world of numbers and statistics – it certainly doesn’t require any detailed knowledge of maths from the reader.

The author gives ten golden rules, or possibly commandments, which we should use when thinking about numbers and statistics with which we are presented. He gives examples to show how we can easily be misled and confused. Themes emerge from the book such as always being curious about numbers, trying to assess how big a number actually is and therefore how significant it is, and finding out how reliable the source is for the numbers quoted. None of this is particularly new to any of us who have listened to the programme but it’s good advice and his examples show us how easily we can be misled and the consequences of not understanding numbers as we should.

This is an engaging book which is written in a light, jokey, style but which actually deals with an important issue. Reading and grasping what the author says here will help us to understand our world better and to avoid being led astray by those who would manipulate figures for their own ends.