 Let's give a little bit of an example of Kirchhoff's current rule. And the current rule, which is also sometimes called the junction rule, deals with the situation where you have current flowing into a junction. Now, as a reminder here, a junction is any place where you've got three wires connecting into a single spot. Now, that means that if you've got a particular corner, that doesn't have a junction because there's only two wires in that spot. So that would not count as a junction. But you can treat it as three wires into a junction. You can even have a situation where you've got four individual segments going into a single junction. Now, notice I call this four wires, not two wires that are crossing each other because they actually all connect at this point. So there's one segment, two segments, three sections, four segments. I'm going to focus most of my stuff on just a three segment joint. But the same principle will work with anything. The general equation for Kirchhoff's rule is that your total current into this junction has to equal the total current out of that junction. I'm going to move this up here so it's out of the way, but we can work on it. Now, sometimes you've got number values and sometimes you've got just symbols for it. I'm going to go ahead and take my currents and just label the current on each branch individually. And it doesn't really matter what you call i1, i2, and i3 unless the problem has already specified some names for certain branches. And then you want to stay consistent with that. But if you're just working on a problem on your own, you can name them however you want to name them. And sometimes you'll have numbers here and sometimes you'll just have symbols here. Well, for this particular case, we would also need to figure out which direction the currents are flowing. So I might be able to put some currents in here. Maybe this current is moving into the junction. Maybe this one is moving out of the junction. And then let's say maybe this one is actually going down, which would be into the junction. Every single one you come across is going to have some sort of different pattern. But once you've got that, then the key is to figure out what you have for your circuit. And I've got an example equation here, but we need to make some changes to it. One is coming in, two is coming in, and three is going out for this particular setup. Depending on the directions of the arrows, that would change which ones are going in and which ones are coming out. And then you would just flip things around in this equation. So for example, if I took this arrow and I actually swung it around and flipped it out, then I would have to change this equation. And I would move the i2 to the other side of the equation to give me that i1 is coming in and 2 and 3 are going out. So that's how you would set it up symbolically. That's an example of Kirchhoff's rule for the current. Now by itself, just as a symbolic equation, it doesn't do much. I'm going to make another video that's going to show you some examples of working with the math for this.