We set up a demonstration of parallel circuitry using 2 light bulbs, 3 D cell batteries, voltmeter, ammeter, paper clips for connecting bulbs, and wire connectors to meters. Once set up, the voltage is measured across each resistance and compared to the total measured voltage. These should be the same. The current in amps is measured across each resistance and the total current measured. The sum of the current across each resistance should equal the total voltage in the circuit. Knowing the voltage across each resistance and the current across each resistance, the resistance in ohms can be calculated for each one. The total resistance determined by the formula 1/Rt = 1/R1 + 1/R2.