Assess students' ability to design a safe LED circuit from a specified battery voltage: calculate the required series resistor using Ohm's law based on LED forward voltage and target current, select an appropriate standard resistor value and power rating (including safety margin), evaluate series vs. parallel arrangements for multiple LEDs, compute power dissipation, and justify choices with step-by-step calculations and brief explanation of safety considerations (tolerances, thermal limits, and current-limiting strategy).