I'm confused about voltage divider circuits. I learned that the output voltage is larger than the input voltage when R1 is smaller than R2. Let's say R1=5Ohms and R2=10 and Vs=9V. Then Vo=6V! Why is the voltage lower? Did I do something wrong? (I used a voltage divider calculator, by the way.) Also, how is electrical ground important in a DC circuit? Why do we use it for a reference point for voltage?