Puzzle Hub

Show the children a simple version of the puzzle hub (two lengths of wire) with the lid off. Have a circuit ready, as shown in the diagram on the worksheet. Attach one of the crocodile clips from the circuit to one of the four ends of the wires in the puzzle hub. Attach the other crocodile clip to the wire the children think might be the other end of it. If the bulb does not light, ask them why this is and try another one until they select the other end of the same wire so that the bulb lights up.

Join the other end to another wire and ask why the bulb doesn’t light.

Next children should make the puzzle hub on the worksheet. A deep ice cream tub is ideal for this activity. Use as many wires as you wish. The wires don’t need to be long, but long enough to knot the two ends of each wire together once they have been identified.

If the children pull a wire, they will see where the other end is, so a ‘no pulling’ rule might be necessary. Or, they could tape the wires to the inside of the tub so the wires won’t move. (See Now try this!)

To organise their testing, children should keep the first crocodile clip attached to the same wire until they have found the other end.

After the children have made the puzzle hub, ask them how they used the circuit to find the other end of any piece of wire. They should explain their answer.

The children can then use the circuit and their puzzle hub wires with the worksheet 2.01: Safety quiz.