## Articles

**Jon Walthoe**explains why Benford's Law says otherwise, and why tax inspectors are taking an interest.

**Helen Mason**explains.

**Robert Leese**explains how the mathematics of colouring graphs can help avoid interference on your mobile phone.

**J.V. Field**continues our series on the origins of proof with an examination of Kepler's astronomy.

**Kona Macphee**investigates.