Review series and parallel circuits and Ohm's law (V = I x R), and review magnet poles and field basics as a bridge into electromagnetism.
A circuit is a complete loop that lets current flow. Ohm's law relates voltage (V, volts), current (I, amps), and resistance (R, ohms): V = I x R. In a series circuit, the same current flows through every part while voltage divides across each. In a parallel circuit, voltage is the same across each branch while current divides between them.
Magnets have two poles, north and south -- like poles repel, opposite poles attract. Every magnet is surrounded by a magnetic field, pictured as lines running from north around to south outside the magnet. Circuits and magnets come together next week to build an electromagnet.
Mastery looks like: They apply V = I x R to solve for voltage, current, or resistance, and predict attraction or repulsion between magnet poles.
Common stumbles: Mixing up which quantity stays the same in series versus parallel circuits; forgetting that like poles repel.