The National Curriculum report on mathematics places a renewed emphasis on the practical uses of mathematical skills and ways of thinking. This work reflects this emphasis in its range of entries. Whilst retaining the information required to understand topics such as directed numbers, mean, root and vector, the book now includes entries on, for example, estimate, half life, hypothsis, linear programming and tree diagram. In addition, the layout of the series has been redesigned for the new edition, and the text completely reset. Illustrations are now expanded upon in linked caption text, increased inter-entry spacing is easier on the eye, and running heads at the top of each page improve quick reference. Richard Browne has revised the text of Gem "Basic Facts: Mathematics" for this edition. He has taught mathematics at secondary level for 11 years, and is presently Professional Officer with responsibility for Mathematics at the School Examinations and Assessment Council.