This fully revised edition is in line with the revised National Curriculum requirements, and focuses on Quantitative Chemistry in Science. Written to match all major GCSE specifications, the text covers all types of numerical questions from first principles. An essential tool for maximising performance in GCSE-level Chemistry. For each topic, a concise treatment of the underlying theory is followed by problems grouped into three sections of increasing difficulty. Calculations based on 'round number' molar masses are included to enable students to concentrate on chemical basis of the problems, rather than arithmetical manipulation.