This text is one of the sequence of textbooks produced for low achievers in the seventh and eighth grades by the School Mathematics Study Group (SMSG). There are eight texts in the sequence, of which this is the fifth. This set of volumes differs from the regular editions of SMSG junior high school texts in that very little reading is required. Concepts and processes are illustrated pictorially, and many exercises are included. This volume deals with decimals (chapter 10) and parallelism (chapter 11). After a brief review of the fundamental operations on whole numbers, the place value system and use of decimal notation are discussed. The decimal point is introduced in the context of the monetary system, and exercises involving conversion from decimal to common fractions, and conversely, are presented. The chapter on parallelism begins with a review of congruence, and relies on constructions in developing the notions of perpendicularity and parallelism. This volume includes tables for addition and multiplication, and flow charts for operations on rationals to be used by students as needed. (SD)