1. Intro to General Chemistry
Significant Figures: In Calculations
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Now when either adding or subtracting different numbers, the final answer will contain the least decimal places. If we take a look at this example, it says perform the following calculation to the right number of sig figs. Now if our answer is based on the least number of decimal places, that's going to have a direct impact on the number of significant figures. If we take a look here, it says we have 402.09 minus 2.12.2 plus 2.671. If we look at these values, this one has 2 decimal places, this one here has 1 decimal place, and this one here has 3 decimal places. Based on that, we're going with the least number of decimal places, our answer can only have 1 decimal place at the end. When we punch all this in, we get 192.561. We can only have 1 decimal place. To the right of that 5, there's a 6 there. That means we have to round up. So this is 182.6 as our final answer, and if you wanted to talk about the number of sig figs, you'd move from left to right. Our first non zero number is this 1, and counting all the way through, we'd have 4 sig figs at the end. K. By following this least number of decimal places, it has a direct impact on the number of sig figs in our final answer. Up to this point, we've kept multiplication and division separate from and subtraction. But what happens when you mix them together? To find out what to do, click on the next video.
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