Mindware.com and other vendors sell a basic, beginner-friendly snap circuit that comes complete with multiple color-coded parts that can be snapped onto the base. Instructions are included with the kit so that you can experiment with aligning the parts in different ways to illuminate simple lights or experiment with a basic fan. This illustrates in a very basic manner how electricity moves from a power source such as a battery to power a device.
Computer engineering is the use of computer programming and coding to control a desired result. A hands-on programming project involves using Lego Mindstorms found at Lego.com. Mindstorms is the name of a battery powered, robot-building Lego set that comes complete with Technic Lego building parts, a microcomputer that acts as the thinking center for the robot, touch sensors, connector cables, interactive motors, color sensors and a CD-ROM that has its own programming language called NXT-G.
Mechanical engineering can be illustrated in a hands-on project that teaches the value of the pulley. Pulleys decrease the amount of force needed to move materials. Have the children try lifting a 10-pound dumbbell using a rope alone and then contrast it to lifting that same weight with the rope threaded through a pulley. Always obtain written permission from parents before performing experiments like this one to inform them of the potential for injury.
Classroom bridge-building kits at teachersource.com include enough wood, adhesive and parameters for 24 students. Students each receive 15 pieces of wood that they can incorporate into their own bridge design. The goal is to design a bridge that can hold the most weight without breaking. Students test how much weight their bridge can hold by incrementally adding weights to their bridge. They can add to the fun by comparing their weight limits with their classmates' bridges.