 OK, so let's do this first short answer problem. It says, the density of mercury, the only metal to exist as a liquid at room temperature, is 13.6 grams per cubic centimeter. What is the density in pounds per cubic inch? And then they give you these conversion factors here. So remember, the hard thing about this one is to remember when the cube is there, you've got to do it three times. So I'm going to write this one out fully all the way across the board. You'll see how it's done. If you do it the long way, you'll never get it wrong. So 13.6 grams per centimeter cubed, like that. So we want it into pounds per inches cubed. So how do we convert grams to pounds? We have a conversion factor up there, right? So we can do that one directly. That one's nice. So 454 grams to 1 pound. OK? So now we're in pounds per cubic centimeter. But that's not what we want, right? We want to do pounds per cubic inch. So we're going to have to do another conversion. So cubic centimeters, well, is this cubic centimeter scary? No, this is just regular centimeters, OK? Is this cubic inches here? No, it's just regular inches. So in order to get cubic inches from regular inches, we're going to have to times it by inch, and then times it by an inch. And that'll give us cubic inches, OK? So let's do that. So on the top, we want centimeters because we want to get rid of them, right? So 2.54 centimeters, 1 inch, OK? That doesn't get rid of centimeters three times, right? So we're going to have to do that two more times. That's what I'm saying. Or qubit? Or qubit, right? But like I said, I wanted to do this one all the way out so people would see it, OK? So that's the second one, right? And then we're going to do it one more time. Let's cancel. So centimeters 1, 2, 3, right? Is that cubic centimeters, right? So we'll just cancel that, put that, that, and that. We multiply inches times inches times inches. What do we get? Cubic inches. Cubic inches, OK? So all we've got to do is multiply all the numerator stuff and then divide it by all the denominator stuff, OK? So let's do that together. So 13.6 times 2.54 times 2.54 times 2.54, OK? And then divide that by 4.54. You should get an answer. And we want it to go to how many sig figs? Three, because there's three sig figs here, OK? So when we do it, I get 0.491 pounds per inches cubed for the density of the mark. Any questions on that one? One. Yes. Does the significant figures in the conversions matter? So the significant figures in the conversions matter? Have we talked about that before? Do they matter then? No, they don't matter, OK? We have talked about them. Yes, you were right. And somebody else was right when they said no. They don't want to use the significant figures for the conversions, because if that were the case, how many significant figures? Yeah, just one. Everything would just have one, right? So no, I don't use it, OK? Any other questions? That's a good question.