Introduce your students to Bridges. This 43 slide Powerpoint provides an overview of scientific concepts of compression and tension;history of bridges; different types of bridges; and examples of bridges around the world. Great for use in Science, Social Studies or Reading Informational Text. Follow this powerpoint with hands on projects where students build basic bridge structures to understand compression and tension concepts. I teach Bridges as a cross curriculum teaching unit in which my students research a particular bridge and develop their own Powerpoint on the bridge; write poetry about bridges; and work in teams to build each of KNEX Bridge Kits; and culminate with a Bridge Exhibition where they show their powerpoint and display their bridge projects.