This study evaluates the Unified Sciences and Mathematics for Elementary School (USMES) curriculum developed by the Education Development Center in Massachusetts. Effects of using USMES materials on students' economic understanding, attitudes, and problem-solving ability were explored. The research also examined the simultaneous relationship between achievement and attitudes. In the study, control and experimental classes were selected on the basis of whether the classroom teacher had participated in a summer inservice program on economic problem solving. Teachers in the experimental inservice group were exposed to basic economic concepts and their application to problem solving in the classroom. Students in their classes worked on an economics-oriented USMES unit,"Manufacturing," during one semester. Teachers in the control group received no instruction in economics or problem solving during the evaluation period. Results indicated that intermediate elementary students significantly improved their economic understanding by working on comprehensive, realistic, and economic-oriented problems as found in the USMES curriculum. These students seemed to develop a substantially more positive attitude toward economics. Also, the program seemed appropriate for both cognitive and affective learning. However, an untrained teacher would probably have difficulty adding an economic dimension to student problem solving from simply reading the USMES materials. Therefore, inservice training will improve teachers' economic understanding and will prepare them for introducing USMES material into the classroom. (Author/KC)