Circuits is a low cost and safe way to teach circuits to students.
All you need to do is put together some ingredients to make some
conductive dough and insulated dough. Once you have the dough you
need a power source and some LED lights and anything else you want
to hook up.
hardest part of this is creating the dough. If you do not have a
kitchen in your building that you can use you would need to do this
at home and bring it in. You can access the recipes for the dough
Dough | Insulated
see examples and get lessons plans click here.