This book meets all requirements of the current Tanzania Primary School syllabus of Science and Technology for Standard 4. In addition to its beautiful layout and richness in illustrations, it contains plenty of science activities which help to build basic investigative skills in a pupil. These activities also help pupils to see how science can explain everyday activities and phenomena. This book builds on a competence-based approach used in similar books for lower classes. Together, our books equip pupils with fundamental skills and knowledge in a manner that relates to real life activities. The language used is simple and straightforward to ensure that pupils easily understand what they read.