Now, the general rule is to follow the following two steps. In step one, we basically want to guess. We want to estimate what the PH value is at which that protein would have a net charge of zero. And then in the next step, we want to use that estimated PH value. In the second step, we want to find the average of the two PKA values right above and right below that estimated PH that we obtained in part one. Now, to actually see these two rules, these two steps in action, let's take a look at these two examples, beginning with example one.