|
Printer-friendly format Email this thread to a friend Bookmark this thread |
This topic is archived. |
Home » Discuss » General Discussion |
masmdu (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 02:18 PM Original message |
Math ... My 8 year old son came up with a way to do multiplication that makes it easy to do large #s |
Printer Friendly | Permalink | | Top |
FiveGoodMen (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 02:20 PM Response to Original message |
1. IOW, 6x = 5x + x |
Printer Friendly | Permalink | | Top |
EOTE (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 02:23 PM Response to Reply #1 |
2. Yeah, that hardly seems significant to me. |
Printer Friendly | Permalink | | Top |
masmdu (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 02:27 PM Response to Reply #2 |
7. But 6* 56 = 5*56 + 56 is not as simple to figure out as when it is divided my 2 then multipled 10 |
Printer Friendly | Permalink | | Top |
EOTE (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 02:30 PM Response to Reply #7 |
11. I think most adults do that automatically. At least with 5s. |
Printer Friendly | Permalink | | Top |
masmdu (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 02:24 PM Response to Reply #1 |
3. yeah but doing division by 2 and multiplying by 10 is much easier to do |
Printer Friendly | Permalink | | Top |
FiveGoodMen (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 02:29 PM Response to Reply #3 |
10. Yeah, I can see how that might help. |
Printer Friendly | Permalink | | Top |
hunter (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 02:25 PM Response to Original message |
4. Check out Trachtenberg system... |
Printer Friendly | Permalink | | Top |
masmdu (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 02:29 PM Response to Reply #4 |
9. Very cool...thanks for that |
Printer Friendly | Permalink | | Top |
Rabblevox (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 02:49 PM Response to Reply #4 |
19. BIG rec to the Trachtenburg System! It saved my maths-challenged butt in Middle-School. /nt |
Printer Friendly | Permalink | | Top |
dsc (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 02:26 PM Response to Original message |
5. Here are a couple of more great tricks |
Printer Friendly | Permalink | | Top |
TlalocW (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 02:31 PM Response to Reply #5 |
12. Squaring numbers in general |
Printer Friendly | Permalink | | Top |
flying rabbit (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 04:03 PM Response to Reply #12 |
24. OK |
Printer Friendly | Permalink | | Top |
buczak (170 posts) Send PM | Profile | Ignore | Fri Oct-21-11 02:26 PM Response to Original message |
6. 11 works similiar |
Printer Friendly | Permalink | | Top |
Fire Walk With Me (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 02:27 PM Response to Original message |
8. It's easier to add large numbers by breaking them down. |
Printer Friendly | Permalink | | Top |
rurallib (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 02:31 PM Response to Original message |
13. great that an 8year old is manipulating numbers like that |
Printer Friendly | Permalink | | Top |
immoderate (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 02:34 PM Response to Original message |
14. He has discovered the associative and commutative properties of multiplication. |
Printer Friendly | Permalink | | Top |
dipsydoodle (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 02:36 PM Response to Original message |
15. So does that work if you want to |
Printer Friendly | Permalink | | Top |
FormerDittoHead (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 02:39 PM Response to Original message |
16. You might find this interesting - Egyptian math. |
Printer Friendly | Permalink | | Top |
Warpy (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 02:45 PM Response to Reply #16 |
18. AKA, "How to Count with your Fingers" |
Printer Friendly | Permalink | | Top |
FormerDittoHead (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 02:57 PM Response to Reply #18 |
20. Really?I don't see how you can do on your fingers what's in the video of Egyptian multiplication.n/t |
Printer Friendly | Permalink | | Top |
Warpy (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 02:41 PM Response to Original message |
17. Double and halve served me better when I was a kid |
Printer Friendly | Permalink | | Top |
EC (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 03:39 PM Response to Original message |
21. Back in 7th grade I was put into an experimental math |
Printer Friendly | Permalink | | Top |
uppityperson (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 03:49 PM Response to Original message |
22. very good for him to figure this out. Is something evenly divisible by 3? Multiplying by 9.... |
Printer Friendly | Permalink | | Top |
hfojvt (1000+ posts) Send PM | Profile | Ignore | Fri Oct-21-11 03:54 PM Response to Original message |
23. not exactly chisanbop |
Printer Friendly | Permalink | | Top |
DU AdBot (1000+ posts) | Fri Apr 26th 2024, 09:14 PM Response to Original message |
Advertisements [?] |
Top |
Home » Discuss » General Discussion |
Powered by DCForum+ Version 1.1 Copyright 1997-2002 DCScripts.com
Software has been extensively modified by the DU administrators
Important Notices: By participating on this discussion board, visitors agree to abide by the rules outlined on our Rules page. Messages posted on the Democratic Underground Discussion Forums are the opinions of the individuals who post them, and do not necessarily represent the opinions of Democratic Underground, LLC.
Home | Discussion Forums | Journals | Store | Donate
About DU | Contact Us | Privacy Policy
Got a message for Democratic Underground? Click here to send us a message.
© 2001 - 2011 Democratic Underground, LLC