Abstract
Bartering problems in arithmetic books appear on the surface to be merely an exercise in the rule of three. However there is a type of problem that contains a surprise for modern readers. This article traces some of the appearances of barter problems in arithmetic textbooks over a period of more than 400 years, and from Italy to England, and examines the methods by which they were solved. It is based on a talk given in Oxford in December 2006 and is part of an ongoing study on this subject. The author would be grateful to learn of further examples in any culture.
Notes
1 The rules of Barter are merely applications of the Rule of Three, and are easily understood.