Resistors in series current question
You are measuring the current through the circuit. By Ohm's Law you know the current through a resistor is proportional to the applied voltage. But what happens when you don't know the voltage across the terminals of the device (i.e. what's the voltage at the middle node of the voltage divider?). 



You can figure that out simply enough if you know the current through the network. Simply combine the resistor into a single component and apply the same rules as if it were a single resistor. 

$$i = \frac{V}{R_3}$$

Where

$$R_3 = R_1 + R_2$$