 So, like I was saying, I guess I kind of gave away the answer to the next question. So let's try to figure out how many secrets there are in each of these numbers. Well of course, like I said in the last problem, the difference between something that has trailing zeroes without a decimal spot, a decimal point, is going to have those zeroes as being insignificant. So this is going to have the one significant digit and the two zeroes are insignificant. But, if we put that decimal point there, then that makes all of those numbers significant. So that's a three, right? And then here, leading zeroes are insignificant always, until the first non-zero number, you don't have any significant digits. So, zero, zero, zero, insignificant. In fact, there's a better way to express this. We'll talk about it. It's called scientific notation. But anyways, this is a good problem because it's got leading zeroes, captive zeroes, and trailing zeroes. So the captive zeroes, like we said, always significant, yeah, always significant. And trailing zeroes are significant if they're after the decimal spot, decimal point. So, what do we got? We've got one, two, three, four significant digits, okay? So, make sure to remember that because, of course, this will be necessary to use in all of your calculations subsequent to this point.