The Zimbabwe Secondary School Science Project (ZIM-SCI) developed student study guides, corresponding teaching guides, and science kits for a low-cost science course which could be taught during the first 2 years of secondary school without the aid of qualified teachers and conventional laboratories. This teaching guide, designed to be read in conjunction with the related student guide, includes instructional strategies, lists of required materials, laboratory procedures, and other information for a two-part unit in which students investigate: (1) the role of food as a fuel; (2) three major food groups (fats, carbohydrates, and proteins); (3) the use of food as a fuel in living things; (4) characteristics and reactions of carbohydrates; (5) digestion; (6) breathing; and (7) photosynthesis. A discussion of how concepts are developed in the unit is provided. Each section in this guide corresponds to a given section in the student study guide. (JN)