EQUALS is a teacher education program that helps elementary and secondary educators acquire methods and materials to attract minority and female students to mathematics. It supports a problem-solving approach to mathematics which has students working in groups, uses active assessment methods, and incorporates a broad mathematics curriculum presented in a variety of contexts. This document is one of a set of five Investigations Units and provides an opportunity for middle school students to acquire some understanding of mathematical concepts related to scale, surface area, volume, and weight. Investigations include: (1) Flea-sized Surgeons Skit; (2) Weight and Surface Area; (3) Surface Area and Volume; (4) Scaling Up To Double Size; (5) Scaling Up Beyond Double Size; (6) Non-Integer Volume and Area; (7) Non-Integer Scale Factors; (8) Shrinking a Real Animal; and (9) Sharing Projects Seminar. Also included are Spanish translations of selected student worksheets and a list of resources. (JRH)