This book has been written to address the requirements of the current Tanzanian Primary school syllabus of Standard 5 Mathematics. It uses a simple language and has plenty of systematic examples for each concept introduced. The over 130 exercises and activities are meant to provide pupils with an efficient means of practicing, revising and testing their underatanding of different concepts. The book builds on a competence-based approach which is a key feature of our similar books for lower classes. Together, these books teach and equip pupils with fundamental skills in Mathematics in an engaging and practical way