Built around a theme of communities in the nation, this teacher's guide for unit eight of a science/math strand for Spanish-speaking children in grade three contains both learning and assessment activities. This unit addresses what the elements are, how needs and wants are satisfied, how change occurs, and what the results of change are. The guide gives focus, objective, and materials for each activity in English and Spanish; detailed teacher instructions are in Spanish. Basic concepts presented are matter, energy, equilibrium, variation, conservation, interaction, adaptation, relativity, change, force, and systems organization. Kits cover pollution--air, noise, solid waste, water, sight; ordinal numbers 1-30; counting by 2's, 3's, 4's; sum of three two-digit numbers; pollution--by nature, effects, control, school/home antipollution campaign; value of coins to $1; addition and subtraction using coins; inverse relation of addition/subtraction; safety--home, electricity, traffic, water, poisonous plants, fire, drugs; first aid; fractions; human body as a group of systems; basic food groups; dental hygiene; diseases; and place value of four-digit numbers. (RS)