Place the series circuit flashcard in a place where the child can see it and ask if he can build this circuit on the board. The flashcard comes in the circuit building toy kit. You can find a circuit building toy kit online or at any hobby store.
Connect the kit's battery to the circuit using the connection cables once the child has built it and let the child flip the switch.
Present the child with the parallel circuit flashcard and ask the child to build this circuit, pointing out the differences as she builds it. Connect the battery and flip the switch again.
Pull out both flashcards and discuss the differences with the child.