These are wonderful. Let me add one of my own to the collection. This is a true story from that same era, maybe a couple of years later when I got kicked out of my third grade class for being a troublemaker and had to go to a special ed class called Mrs. Spencer's Workshop.

199. Make your own printed circuit board

You will need: a common kitchen cutting board, a sheet of copper, a roll of electrical tape, a fish tank, and a supply of nitric acid. And whatever electrical components you need to complete your circuit.

All of these supplies are readily available to a third grader, except for the nitric acid which you will have to ask your teacher to source.

First, design your circuit and test it in your mind. Then tape it out - literally - with the electrical tape on one side of the copper sheet and matching tape on the other side.

Pour the nitric acid into the fish tank.

Dip the copper sheet into the nitric acid. Watch it with your teacher as the acid dissolves the copper, except where you have taped out your circuit.

When all that remains are the taped out traces, remove the copper circuit from the acid and rinse it with water.

Peel off the electrical tape and fasten the copper traces onto the cutting board. This is what makes it a circuit board.

Connect the rest of the components and test your circuit.

Go to the science fair, demonstrate the printed circuit, and explain to the visitors how you made it.

Thank you, Mrs. Spencer.