This teacher's guide offers classroom techniques for teaching science to bilingual elementary students. Recommendations are made for improving teaching by: lowering students' affective filters; providing comprehensible input; providing for language output; creating a supportive environment; adjusting classroom teaching style; teaching heterogeneous groups; motivating participation; using students' background knowledge; and providing concrete support for student efforts. A sample unit entitled "What Is Science?" is outlined in seven detailed and varied classroom activities. (MSE)