How is the resistance in a DC circuit calculated when the voltage and current are known?

Ohm's Law provides the mathematical relationship between voltage, current, and resistance in a DC circuit. The standard formula is E = I x R, where E is voltage, I is current, and R is resistance. If you know the voltage and the current, you can solve for resistance by rearranging the formula to R = E / I. This means resistance equals voltage divided by current. Distractors that multiply current and voltage are actually describing the formula for electrical power (Watts). Dividing current by voltage calculates conductance, which is the reciprocal of resistance, not the resistance itself.