Timeline for How to teach addition of negative numbers?
Current License: CC BY-SA 2.5
11 events
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| Dec 5, 2009 at 20:29 | comment | added | José Figueroa-O'Farrill | @fpqc: I tend to agree, whence my disclaimer that this may not really help the person in question. I mentioned it because (1) the OP was asking about different models of negative numbers, and (2) it may very well be (I speak from ignorance here!) that people afflicted by dyscalculia might follow non-standard paths to certain mathematical notions. And who knows? Perhaps one does not need prior understanding of negative numbers in order to compare positive numbers, which is all that the Grothendieck construction is doing? | |
| Dec 5, 2009 at 20:24 | comment | added | José Figueroa-O'Farrill | Sorry, by nature I mean Physics. One never really measures negative numbers. Sure, apparata often read negative numbers, but that is only because internally they are doing a comparison between two positive quantities. | |
| Dec 5, 2009 at 20:21 | comment | added | Harry Gindi | @Jose, whence came the +1 for boldness. I just don't know how much this would help someone who doesn't already understand negative numbers. | |
| Dec 5, 2009 at 19:35 | comment | added | Kevin H. Lin | Sure negative numbers arise in nature. Surely you'll agree that the notion of orientation exists in nature. Negative numbers are just positive numbers with the opposite orientation, as explained in javier's answer. | |
| Dec 5, 2009 at 15:37 | comment | added | José Figueroa-O'Farrill | It's actually extremely useful. It's Grothendieck's construction of the K-group of a commutative monoid, which forms the basis of K-theory :) | |
| Dec 5, 2009 at 14:46 | comment | added | Anna Varvak | I just realized that the chips model that I provided in my comment is a physical model of exactly what Jose describes: operations with a pair of numbers. It also happens to be the classic accounting model of debits and credits, so it is all kinds of useful. | |
| Dec 5, 2009 at 13:59 | comment | added | José Figueroa-O'Farrill | I was being serious. :) | |
| Dec 5, 2009 at 13:27 | comment | added | Harry Gindi | Like spicy salsa or something ;). | |
| Dec 5, 2009 at 13:27 | comment | added | Harry Gindi | I'm not sure if this answer was serious, but I'm giving a +1 for boldness. | |
| Dec 5, 2009 at 13:00 | history | edited | José Figueroa-O'Farrill | CC BY-SA 2.5 |
Added motivation for pairs.
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| Dec 5, 2009 at 10:59 | history | answered | José Figueroa-O'Farrill | CC BY-SA 2.5 |