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MentalCalculation · Mental Calculation

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  • Members: 1115
  • Category: Mathematics
  • Founded: Oct 8, 2002
  • Language: English
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Messages 2205 - 2235 of 4924   Oldest  |  < Older  |  Newer >  |  Newest
Messages: Simplify | Expand Author Sort by Date ^
2205 markhilton2000 Send Email Jun 2, 2007
7:41 am
The link you provided didnt work, what I was wondering is there a place on the internet with free games that help you train your memory and help you develop...
2206 jean
jean2ms Send Email
Jun 2, 2007
8:29 am
Remove the point of the adress. Regards. markhilton2000 <markhilton2000@...> a écrit : The link you provided didnt work, what I was wondering is there a...
2207 David Raju
mathsdavid Send Email
Jun 3, 2007
8:28 am
Hellow,pi world ranking has been updated. visit:http://pi-world- ranking-list.com/lists/memo/index.html...
2208 Mick Curtis
mick_curtis Send Email
Jun 4, 2007
12:49 pm
silly question? But if a school child asked the question, what would be an inspirational answer? Historically, when would the ability to square root quickly...
2209 retothejuggler Send Email Jun 4, 2007
12:56 pm
Hello all from my childhood I was fascinated by reading about mental maths, however, I never got significant results and I picked up other things as well. But...
2210 nodden_1984_mes_gr
nodden_1984_... Send Email
Jun 5, 2007
4:28 pm
Hi there. Square roots are very important because it's the inverse of finding the square of a number. Nodas...
2211 nodden_1984_mes_gr
nodden_1984_... Send Email
Jun 5, 2007
4:53 pm
... things ... a ... find/ ... right? ... multiplying ... Sticker? ... you ... multiplication? ... usually ... concentration, ... Hi my friend! Speed math...
2212 retothejuggler Send Email Jun 5, 2007
6:41 pm
Hello Nodas nice to read from you!..thanks for answering this patiently. To give you my earlier results found in an old listing: I factorized all numbers up to...
2213 markhilton2000 Send Email Jun 6, 2007
7:55 am
... I love this tool: http://www.jimmyr.com/blog/speed_math.html I wish there were more tools like this to help me with mental calculation training and memory....
2214 nodden_1984_mes_gr
nodden_1984_... Send Email
Jun 6, 2007
3:08 pm
Hello Reto thx for replying For 1 on 5 digits multiplication good result would be for me if it's done within 10-20 seconds. And the one digits won't be 2,3,5...
2215 P Scott Horne
patrick.horne@... Send Email
Jun 7, 2007
4:15 pm
... Better to do it as 34 × (100 - 14) = 34 × 100 - 34 × 14 34 × 14 = 24² - 10² = 576 - 100 = 476 3400 - 476 = 2924 Scott Horne...
2216 Oleg Stepanov
olegstepanov@... Send Email
Jun 7, 2007
8:04 pm
34x86=34x50+34x36=1700+1225-1=2924 ... PSH> Better to do it as PSH> 34 × (100 - 14) = 34 × 100 - 34 × 14 PSH> 34 × 14 = 24² - 10² = 576 - 100 = 476 PSH>...
2217 rondrond1 Send Email Jun 8, 2007
7:24 am
Interesting. I would have done it this way, since 34 is so near a third of 100: 34x86=(102x86)/3 = (8600+172)/3 = 8772/3 = 2924 A short division like this at...
2218 Emmanuel/DATA
emmanuel_dub... Send Email
Jun 8, 2007
11:53 am
34= 50 -16 86=100-14 14/2= 7 34-7=27(00) 16x14=224 27(00)+224=2924 Emmanuël rondrond1 <rondrond1@...> a écrit : Interesting. I would have done...
2219 Oleg Stepanov
olegstepanov@... Send Email
Jun 9, 2007
11:17 am
ED> 34=50-16 ED> 86=100-14 ED> 14/2=7 ED> 34-7=27(00) ED> 16x14=224 ED> 27(00)+224=2924 ED> Emmanuël Too long and difficult. ...
2220 Emmanuel DUBRULLE
emmanuel_dub... Send Email
Jun 9, 2007
5:26 pm
The written process seems long to you, but actually it's much simpler because I rather work in visual mode and not purely arithmetic. I read 34 x 86 I see 224...
2221 Michael Curtis
mick_curtis Send Email
Jun 9, 2007
6:28 pm
If someone could wave a magic wand and you guys could know the 100 times table without needing to do sub calculations, would you feel sad about it? Is your...
2222 Emmanuel DUBRULLE
emmanuel_dub... Send Email
Jun 9, 2007
7:04 pm
It's not necessary to know the table up to 100 x 100; I know it up to 30 by 30 , but did not study; I have a cartography of the table in my head, I designed...
2223 Michael Curtis
mick_curtis Send Email
Jun 9, 2007
7:47 pm
I read recently about a chap named Cohen. An example was given of his ability to factorise a 6 digit number. I looked up factorisation web pages and saw one...
2224 Michael Curtis
mick_curtis Send Email
Jun 10, 2007
8:11 am
Fermat. Sorry. I woke up and the right name came to mind. Mike ... From: Michael Curtis <mick_curtis@...> To: MentalCalculation@yahoogroups.com Sent:...
2225 Oleg Stepanov
olegstepanov@... Send Email
Jun 10, 2007
12:29 pm
AxB=? A=50-a B=100-b AB=(B/2-a)[00]+ab 86/2=43 43-16=27 2700+224=2924 Just idea. ED> The written process seems long to you, but actually it's much simpler ED>...
2226 marziya_d Send Email Jun 10, 2007
5:14 pm
I am a new member. I am interested to memorise calendar. Will anybody help me out as to how do i start in this matter. Is there any book on this subject or any...
2227 Andy Robertshaw
robertshaw_andy Send Email
Jun 10, 2007
6:07 pm
Hi! Ok, here are a few tricks: Firstly, it is good to know a few starting points, eg. On which day of the week was your own date of birth? How about those of...
2229 Oleg Roitman
mentalmathan... Send Email
Jun 12, 2007
4:45 pm
... to ... I beg your pardon for my poor English! I would say there are two schools of thought. One way you can read everything you can find about the topic...
2230 javiergijn Send Email Jun 12, 2007
10:15 pm
Yes, i know its late , but i read the last messages now. I prefer this way : In 34 x 86 I hear "seventeen , seventeen.." , i.e. 34 x 86 = 17 x 17 2 = 289 (x...
2231 susan abraham
susaan46 Send Email
Jun 13, 2007
8:15 am
Sorry , I am later to reply. The best way to multiply any two digit numbers is to learn abacus. My students can easily do these. But it is possible only upto...
2232 Emmanuel/DATA
emmanuel_dub... Send Email
Jun 13, 2007
11:44 am
I dot not believe there is a "best" way - the idea is a bit dogmatic*; although I have seen very skilled calculator even using mental abacus. A cartography of...
2233 jyoti rane
jyorane Send Email
Jun 14, 2007
10:51 am
hi Can u pls explain how did u arrive at this? Thanks Jyoti Rane ... From: javiergijn <fabesconalmejes@...> To: MentalCalculation@yahoogroups.com Sent:...
2234 tradewebhosting Send Email Jun 14, 2007
6:08 pm
How did you come to 17 x 172 = 289 x 10 is there some quick way. Mark Yes, i know its late , but i read the last messages now. I prefer this way : In 34 x 86 I...
2235 cal_q_layton Send Email Jun 14, 2007
6:56 pm
... Here's what Javi was getting at: 34 is a multiple of 17. (2x17) 86 is CLOSE to a multiple of 17. (5x17 + 1) So 34 x 86 = (2 x 17) x [(5 x 17) + 1] = [(2 x...
Messages 2205 - 2235 of 4924   Oldest  |  < Older  |  Newer >  |  Newest
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