How much a material resists the flow of charge.

The opposition to current flow in a circuit element.

The electrical potential difference that drives current.

The rate of flow of electric charge.

A fundamental property of matter that can be positive or negative.

Energy associated with electric fields and charges.

The rate at which electrical energy is used or generated.

Add the individual resistances: $R_{total} = R_1 + R_2 + R_3 ...$

Use the reciprocal formula: $\frac{1}{R_{total}} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} ...$

Sum the individual currents: $I_{total} = I_1 + I_2 + I_3 ...$

Sum the individual voltages: $V_{total} = V_1 + V_2 + V_3 ...$

$V = IR$

Series: Same current, total resistance is the sum, voltage divides. Parallel: Same voltage, total resistance uses reciprocal, current divides.

Series: Voltage is divided among components. Parallel: Voltage is the same across all components.

Series: Current is the same through all components. Parallel: Current is divided among components.

Series: $R_{total} = R_1 + R_2 + R_3 ...$ Parallel: $\frac{1}{R_{total}} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} ...$