This book discusses about the steps of test construction and standardization process of Reasoning Ability Test in Mathematics [RATM] with detail. This book is depending upon the work of doctoral research on RATM standardization. It is divided in to different eight chapters. This book is useful for new test developers, researchers and teachers. The RATM is also useful tool for teachers, parents and researchers. RATM is developed for Gujarati medium school students to measure their reasoning ability in mathematics.