Crocodile Clips

Nick Packard
This article first appeared in MAPE Focus on Science Autumn 2000

Every teacher must have experienced that sinking feeling as they drag the bulbs, batteries, wires and . . . crocodile clips . . . out of the cupboard to 'do' circuits again this year. And then only to find that half the batteries are dead, several of the bulbs got blown last year (when one or two of the little darlings finally learnt how to put seven batteries in series and marvelled at how brightly the bulbs shone, even if it was only for a short while), several of the clips have parted company from the wires and . . . well, you get the picture. Doing the work, the thrill of discovery, the wonderful discussions and hypothesising; it's all good stuff but we could really do without the logistical nightmares.

Now, try it again, but this time in a 'perfect world' . . . the batteries never run out, the bulbs are indestructible, there are always plenty of wires and connectors, the pack even includes all sorts of extra bits and bobs like buzzers, variable resistors, LED's, and all of them work every time you use them. And it's all totally free!

It might sound a bit unlikely, but this is really a pretty accurate description of a piece of really a pretty accurate description of a piece of software called Crocodile Clips. On-screen tools allow kids to select basic pieces of virtual electrical equipment, it's easy to connect these together by clicking and dragging virtual wires between the terminals and the really nice bit is that when a virtual switch is thrown (it rocks when you click on it) the virtual bulb virtually lights or the virtual buzzer actually buzzes. Nicer still, add another bulb to the circuit and both bulbs light, but less brightly than before, just like in real life (assuming you found the two bulbs that still work in real life).

As pupils become more familiar with the tools and strategies, there are teaching elements available in the package which may help more able and older children to learn about typical applications of simple circuits more independently. They describe and illustrate how the basic elements of circuits are used in the world around us. The descriptions use fairly simple language and the illustrations are clear. They cover topics from a very basic circuit, to series and parallel connections to doorbells and dimmer switches.

There is also a quiz to act as a form of self assessment tool.

Of course there are limitations to teaching primary age children about electrical circuits in this way. Just because it happens on-screen, it doesn't necessarily prove that it will actually happen that way in real life.

However, establishing an idea on screen, where you can drag and drop the elements of a circuit, change elements with a couple of clicks, and then test it out in real life might be a lot quicker and easier than doing everything from scratch with the real McCoy. Bulbs blowing up and batteries going flat might be a learning outcome you are happy to do without!

It is a piece of American software (though its ancestors are actually buried on British soil!) and, as such, is aimed firmly at the American schools market. This piece of software (the free bit) is intended for 'elementary' schools; there is another piece of software, (much more sophisticated and definitely not free) intended for High schools.

Some of the language is in American English but this is a small price to pay for a simple, robust and effective program for tackling circuit work in Primary schools.

OK, it might not be quite the 'perfect world' we would have wished for. Clearly there are disadvantages in trying to teach pupils about circuits this way, but with a bit of careful bridging between the real and the virtual worlds, Crocodile Clips may prove to be an extremely useful piece of software for teachers in Primary schools who want to provide new opportunities for their pupils.

This is an effective use of a computer for modelling events in the real world so you're supporting the IT curriculum, but it's good science work, too. If you want to get in on the act, why not download Crocodile Clips from

All it'll cost you is the price of your e-mail address when you register.

Editor's note

In order to download the software you must register by typing your address and e-mail number. From the home page click 'Download a free demo' under Crocodile Physics then from the left hand menu choose 'Free Stuff' and click to download Crocodile Clips Elementary. You will be asked if you wish to save the program to disc and you can choose where to file it. The download then takes about 5 minutes using a standard telephone line.

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