"Knowledge Promotion" is the recent curriculum for the Norwegian 10-year compulsory school. "Technology and Design" (ToD) is a new main subject area in Natural Science. ToD should be taught across the curriculum between Natural Science, Art and Crafts, and Mathematics. The main goal is that pupils should be able to plan, develop and make useful products. The interaction between natural science and technology is a key part of this main subject area. Natural science principles constitute the basis for understanding technological activities. The present analyses of ToD education is based on case studies in three schools. The main outcome is that the actual ToD-project seems successful in developing pupils' skills in designing and making products, and has great potential to be a vehicle for enhancing understanding of adequate natural science principles. If carefully planned, this conclusion might be generalized to other ToD-projects. (Contains 1 table and 3 figures.)