Including the correct terminology is essential to any building bridge lesson. By providing elementary students with engineering- and bridge-related vocabulary words, you will give them a means to appropriately discuss what they are learning and building. Start simply with the names of different types of bridges. A truss bridge is made of steel bars assembled in a series of triangles; arch bridges are reminiscent of ancient Rome and use engineered steel or concrete curved shapes; and suspension bridges rely on cables to secure their structure. After teaching the students about the bridge types, move into more advanced or specific terminology including materials that bridges are made from, such as steel or concrete, as well as discussing beam, cantilever and covered bridges.
Actually viewing bridges, or pictures of the structures, should be an integral part of an elementary school lesson on the subject. If you are lucky enough to have a bridge nearby, or will be going on a field trip near bridges, use this time to have the students take a look at the real thing. Discuss what they see, what type of bridge it is and what they think the functions of the bridge may be. Teachers and parents trying a bridge-building lesson with their elementary school students who do not have a nearby real-life example can substitute with photographs. Either take a picture of a bridge from your town or use a photo from a nonfiction book.
Before they try building a bridge model of their own, encourage students to draw a blueprint of their design. Discuss form and function, and ask the students to choose a specific type of bridge style that matches the use they plan for it. Provide the children with pencils, rulers and white drawing paper to make a mockup drawing of their structure. Older elementary school students in grades 4 and up can learn about math ideas such as scale, shape and symmetry by making measurements and using geometry.
Choose a variety of materials such as toothpicks, craft sticks, cardboard, string or yarn and clear drying school glue for building bridge models. Have children use a rectangular piece of cardboard as a base. Select the size based on the size or scale of the bridge. For example, if your students will be making a 2-foot-long model, you will need a piece of cardboard that is at least a few inches larger on each side. Use toothpicks or craft sticks to build a bridge span or the triangles of a truss. Attach the toothpicks or sticks together with a dab of glue, or even use a small piece of modeling clay to connect the pieces at each end. String or yarn can replace the wire of a suspension bridge. For an added realistic look, glue blue cellophane or tissue paper onto the cardboard as a river or creek.