Melissa in Australia Posted May 13, 2010 Share Posted May 13, 2010 DS16 is 1/2 way through Apologia physics. he has found the way they do significant figures and rounding very frustrating. in fact he has spent up to 2 days on one problem, trying to get the exact answer in the book ( he is a bit pedantic) when he was at a science and engineering challenge at a big university last week. He took the opportunity to ask the professors about significant figures.He will probably go to the university he visited. they told him that how significant figures are done at university is that you don't round to significant figures until the final answer. If you need to record the answer to certain steps throughout the problem, then you record the answers in significant figures, but keep the actual answer in your calculator and keep working with it. The professors said that continually changing to significant figures and rounding throughout the whole problem leads to too many inaccuracies! Which is just the way we thought it should be! My DS16 wants to continue using Apologia, because he is 1/2 way through it, and would rather finish one book than switch, and have to re-do work. The problem is, how will I be able to mark his work? he is going to have different answers to the book! Does anyone have any more advice on significant figures? Quote Link to comment Share on other sites More sharing options...
Susan C. Posted May 13, 2010 Share Posted May 13, 2010 I didn't mark anything wrong that was close to the answer. If the answer is close, then you know the problem was set up and done correctly. We did BJU for 8 wks, then switched to Apologia. BJU showed how to do significant figures correctly, but then the teacher said he wouldn't mark down for answers that were close, and ranges were given for answers. If your son wants to learn significant figures correctly, let him, and if the answers are close to those in Apologia, you are good! Quote Link to comment Share on other sites More sharing options...
Musicmom Posted May 13, 2010 Share Posted May 13, 2010 We ran into this same frustration with Apologia physics. What made it even more frustrating was that it seemed the solution manual didn't deal with the significant figures in a consistent way--sometimes they rounded partway through the problem, and sometimes not until the end. It drove ds crazy! We finally emailed Apologia about it and got a very nice (and quick--within 4 hours) response. Basically, they said not to worry about the small discrepancies between their and ds's answers. So, like Susan, I also didn't mark anything wrong that was close, and we finished the course without losing any more hair over it! :001_smile: Quote Link to comment Share on other sites More sharing options...
MyThreeSons Posted May 13, 2010 Share Posted May 13, 2010 The problem is, how will I be able to mark his work? he is going to have different answers to the book! Does anyone have any more advice on significant figures? Did you go online to the errata page for your edition of the text? (There is info in the front matter of the text to tell you how to get to the "extras" page, where you will find a link to the errata info.) A lot of the errors they have posted have to do with incorrect number of significant figures. I have told my co-op students not to sweat it. I don't want to see them writing down a answer to 8 places past the decimal point just because that's what their calculator shows, but I don't take off points for it. BTW, when I was in college (engineering major), we didn't worry about sig figs in textbook problems -- there we considered the values to be precise. When we were doing calculations for our labs, however, we took sig figs into consideration based on the precision with which we could measure the values. Quote Link to comment Share on other sites More sharing options...
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