voltage divider

What are you talking about? Voltage isn't sent to ground like you are saying here. There is a voltage drop across each resistor. Using Kirchhoff loop rule, we know that if you do a loop around the circuit the sum of the voltage drops/gains equals zero. So the voltage source is a gain of four volts, the first resistor is a loss or drop of two volts the second resistor is a drop of two volts. 4-2-2=0. So that proves what you are seeing here. You could also figure out the voltage drop by taking the current through that resistor and multiplying it by the resistance, this is ohms law, v=ir, where v is voltage, I is current, and r is resistance... finally what you have here is a voltage divider. If you change the resistance on either value it would affect the voltage drop across each resistor. For a voltage divider, the voltage at the node between the resistors is v_out=((R_2)/(R_1+R_2))*v_in. Since both values are the same you get a 1/2 ratio, you can adjust the ratio Accordingly to get the desired voltage out.