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Posted: Tue Oct 01, 2019 10:05 pm
When it comes to rounding when the digit after the last digit you keep is 5, how should we do it? I've learned to round down if the previous digit is even, and up if the previous digit is odd, but I'm not sure if that's standard convention. For example, if I only wanted 2 sig figs and the number in question was 1.65, I would round down, but if it was 1.35, I would round up. Is this right?
Posted: Tue Oct 01, 2019 10:08 pm
If the number is 5 or greater, you would round up. So in the example you gave, if you only wanted 2 sig figs, 1.65 would then become 1.70, and if the number was 1.35 it would become 1.40 and so on.
Posted: Tue Oct 01, 2019 10:09 pm
Yes you're right. Mr. Lavelle's website says that you round to the nearest even digit if the last number if 5 so you are correct for rounding 1.65 to 1.6 and 1.35 to 1.4
Posted: Tue Oct 01, 2019 10:45 pm
The only difference between rounding and chemistry rounding is when the last digit is a 5. When you have a number that ends in 5 (ex: 3.65), you round up or down to the nearest even number. In the example, it would be 3.6. However, if you had 4.75, you would round up to 4.8.