1. The problem statement, all variables and given/known data Find the power absorbed by each element in the single node pair circuit of the figure, and show that the sum is equal to zero. 2. Relevant equations Kirchhoff's current law... in current = out current 3. The attempt at a solution This is the solution. I have the solution (see below). However I hope someone can help me understand how they chose the direction of current for Kirchhoff's current law. I can visualize the 8 amps turning right and going into the middle node. The 7 amps is clearly going into the node. However, I'm not sure about how they know what signs to use for the current through all the resistors. I know at least one of the currents through the middle node must go out. I'm wondering if it has to do with the fact that they define the positive voltage at the middle. I'll just confuse myself if I keep guessing though. Thanks for any help.