The purpose of this unit is to explore structures and the forces that act on them.  Through language, mathematics and science activities students will learn about the structures found in nature and study some historical man-made structures.  We will explore the different types of bridges and their advantages.  Activities will be small/whole group/individual in nature and address several specific strands at each junior grade level.  The groups will design, buy materials and build a bridge to specifications and it will then be tested against the other groups in the class. Construction is expected to have consideration of the tension and compression acting on bridges as well as the daily effect of traffic and natural forces.  The bridge will then be measured and tested with a load.