This book is the teacher's manual to a text designed to meet the particular needs of those children who have "accumulated discouragements" in learning mathematics. It is a manual of suggested teaching strategies and additional materials aimed at compensating for past student failures to understand mathematical concepts. This book, L, is designed for the fourth-grade mathematics program. Individual chapter titles are: Properties; Geometry; Fractions; and Techniques of Addition and Subtraction of Whole Numbers. (MP)