This book deals with the mathematics of the medieval West between ca. 500 and 1100, the period before the translations from Arabic and Greek had their impact. Four of the studies appear for the first time in English. Among the topics treated are: the Roman surveyors (agrimensores); recreational mathematics in the period of Bede and Alcuin; geometrical texts compiled in Corbie and Lorraine from Latin sources from late antiquity; the abacus at the time of Gerbert (pope Sylvester II.); and a board-game invented in the first half of the 11th century (the 'Rithmimachia') to help people to learn mathematics. Included in the volume are critical editions of several texts, e.g. that of Franco of Liège on squaring the circle, Bede and Alcuin on recreational mathematics, and part of Pseudo-Boethius' Geometry I. The book opens with a survey of mathematics in the Middle Ages, and ends with a history of Rithmimachia up to the 17th century, when the game fell into disuse.