The ÔsonaÕ tradition belongs to the culture of the Cokwe and related peoples in Eastern Angola and neighboring areas of Northwest Zambia and the Congo. Observers have described ÔsonaÕ as sand graphs, sand drawings, drawings in the sand, writing in the sand, pictographs and ideograms, and as a system of communication. The ÔsonaÕ tradition is multifaceted. It comprises aspects that are philosophical, educational, artistic, ideographic, and recreational. The book shows that mathematical considerations were involved and developed as the Cokwe invented ÔsonaÕ and built up a reservoir of symbolic-graphic expressions. The book presents an analysis and reconstruction of mathematical elements in the sona tradition. The first English language edition in color contains an updated bibliography and an appendix with a brief introduction to new mathematical ideas that came out of the study of Ôsona.Õ Translation and Preface: Artur B. Powell, Rutgers University, Newark, USA; 248 pp., over 500 illustrations in color.