Visit any school science fair and you're bound to see a few familiar, tried-and-true experiments that have introduced generations of students to the principles of electricity. Here's a popular example that can be recreated using the iPad.

Image from How to Make Electricity (Crayon Box)

Have you ever had your students try generating electricity with a nail, a copper key, and a can of cola? How to Make Electricity (Crayon Box, iOS, $2.99; Gr 4-7) offers this experience (and others) without the necessity of purchasing supplies. Divided into four separate laboratories, the app allows users to simulate electricity through batteries as well as hydroelectric, thermal power, and solar generation. Each lab begins with a brief tutorial provided by an animated box of crayons; users follow prompts to explore the variables in the experimental setup. Unfortunately, the tutorials are all text based, and do not have an accompanying narration, making the app less accessible for struggling readers. After each tutorial, users are challenged to design a configuration that will generate the most electricity. For example, in the thermal power lab, students attach a magnet to a pinwheel, and then test the results using different fuels, such as coal, paper, and wood. They can also alter the shape of the coil, change the placement of the pinwheel, and swap in different devices and appliances such as a fan, a light bulb, or speakers. Users are awarded a “Discovery” when they create lab conditions that demonstrate an important principle. A battery on the outside of each lab door indicates how many discoveries have been made. The attractive and colorful graphics will immediately engage viewers. The app includes an especially thorough and well-designed “Parents Guide” that translates well to a classroom setting. It offers suggestions of questions and discussion topics to consider and introductory lessons and activities that pair with the four lab set-ups. VERDICT The app is well-suited as an accompaniment to upper elementary or middle school classrooms studying electricity.—Lindsay Cesari, Baldwinsville School District, NY