In a series circuit, where multiple resistors are connected end-to-end, the total resistance (R_total) can be calculated by simply summing up the individual resistances of all the components. Mathematically, for n resistors in series:
R_total = R1 + R2 + R3 + ... + Rn
Where R1, R2, R3, ..., Rn are the resistance values of the individual resistors.
So, to calculate the total resistance in a series circuit, you just need to add up the resistance values of all the resistors connected in series. This is because the current has only one path to flow through all the resistors, and the total resistance determines how much the circuit resists the flow of current.