The Math Clues Series helps students gain a clear understanding of basic mathematical concepts. The relationship of one concept to another is demonstrated throughout the series. The language of mathematics is precise and the skill of each concept is fully developed with lessons, practice, and motivating story problems. Each book is divided into three sections. In Introduction and Review each concept and procedure is clearly explained. Each lesson in Skill Building Word Problems deals with a particular skill, and students are aware of the skill. In Challenge Word Problems the skills are mixed, and students must decide which skills or skills are involved.