This guide is intended to assist Latin and English teachers who have some background in Latin to expand the English vocabulary and reading skills of students through the study of Latin roots, prefixes, and suffixes. The lessons on numbers in Latin are designed to be presented through an audiolingual approach. The introductory material in the guide provides general notes on the teaching of Latin in the Philadelphia School District, suggestions for scheduling and staffing the Latin classes, an outline of the organization of each lesson, some general hints to the teacher, and an overview of the material to be taught in this unit. The presentation of the material is organized in nine lessons, each one containing objectives, exercises, explanatory material, and word games. The appendix is an explanation of the ancient method of counting. (AMH)