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## #26 2006-12-16 15:12:31

Toast
Real Member
Registered: 2006-10-08
Posts: 1,321

### Re: Mental arithmetic making you look bad?

There's a website named after that, so I'm not sure that would be a good idea...

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## #27 2006-12-16 19:57:25

Devantè
Real Member
Registered: 2006-07-14
Posts: 6,400

Mathalympics?

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## #28 2006-12-16 20:21:26

mikau
Member
Registered: 2005-08-22
Posts: 1,504

### Re: Mental arithmetic making you look bad?

ARe they held in Mathens Greece?

Sorry I couldn't resist :-P

A logarithm is just a misspelled algorithm.

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## #29 2006-12-16 20:22:09

Devantè
Real Member
Registered: 2006-07-14
Posts: 6,400

### Re: Mental arithmetic making you look bad?

No, in Mathland. Next to Cleveland.

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## #30 2006-12-16 20:29:09

mikau
Member
Registered: 2005-08-22
Posts: 1,504

### Re: Mental arithmetic making you look bad?

Lol!

A logarithm is just a misspelled algorithm.

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## #31 2006-12-18 15:38:40

MathsIsFun
Registered: 2005-01-21
Posts: 7,684

### Re: Mental arithmetic making you look bad?

OK. I have a version of Reaction Math for you to try out.

I can do "Add Single" with an average under 1 second. Beat that. Then have a go at 10x10.

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

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## #32 2006-12-18 16:38:59

George,Y
Member
Registered: 2006-03-12
Posts: 1,316

The game is fun!

X'(y-Xβ)=0

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## #33 2006-12-18 18:10:10

justlookingforthemoment
Moderator
Registered: 2005-05-26
Posts: 2,161

### Re: Mental arithmetic making you look bad?

MathsIsFun wrote:

I can do "Add Single" with an average under 1 second. Beat that.

Well, 0.735 seconds for add single and 0.969 for multiply 10x10 (with all correct!). I'm sure someone will easily beat them but I thought I better make a start ...

I kept getting all the answers wrong, even though I entered the right numbers. It kept saying, '1 + 2 = 3 (not 3)' etc. And I kept getting 50% each time. Then I realised you don't need to press enter after keying in each number ...

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## #34 2006-12-18 18:16:55

mikau
Member
Registered: 2005-08-22
Posts: 1,504

### Re: Mental arithmetic making you look bad?

Great stuff, mathsisfun! Its perfect!

The only other possible type of practice I can think of is if the numbers are either spoken or displayed briefly. A big problem with me when doing mental math is I often forget what the numbers were!

But again, great job! And I must say! You certainly are very devoted to  making this website the best it can be! When you get a good idea you don't waste any time doing it! (unlike some people) And you seem ever willing to do more! And might I add you do a nice job as well! It was uncanny how quickly you threw together that polar grapher!

Now I and many others have got a great practice tool to work with for mental arithmetic!

You da man!

(edit) and a highscores board would be cool if possilbe! :-)
Its pretty cool that you can use they keypad. If your fast with it then entering the number doesn't slow you down at all.

Last edited by mikau (2006-12-18 18:32:31)

A logarithm is just a misspelled algorithm.

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## #35 2006-12-18 18:42:15

Patrick
Real Member
Registered: 2006-02-24
Posts: 1,005

### Re: Mental arithmetic making you look bad?

Awesome ! Love the game Rod

Support MathsIsFun.com by clicking on the banners.
What music do I listen to? Clicky click

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## #36 2006-12-18 23:18:02

Toast
Real Member
Registered: 2006-10-08
Posts: 1,321

### Re: Mental arithmetic making you look bad?

Hmmm. I'm having problems with it. Even if I type the correct answer it still marks it wrong (you can see by the log it keeps)

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## #37 2006-12-19 00:31:01

LQ
Real Member
Registered: 2006-12-04
Posts: 1,285

### Re: Mental arithmetic making you look bad?

MathsIsFun wrote:

"Velocity Math" is cool ... or maybe "Reaction Math"?

Or "Sum Sum"

Last edited by LQ (2006-12-19 00:34:04)

I see clearly now, the universe have the black dots, Thus I am on my way of inventing this remedy...

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## #38 2006-12-19 01:14:46

mathsyperson
Moderator
Registered: 2005-06-22
Posts: 4,900

### Re: Mental arithmetic making you look bad?

I'm not sure why it's not working for Toast, because it works very well for me.

I've only done the Add Single so far, but I've been able to do that without any problems. And my average time was 0.646s.

Toast, are you pressing enter after you type your numbers? Because you shouldn't be. Justlooking had that problem as well.

Edit: 0.801s for 10x10.

Why did the vector cross the road?
It wanted to be normal.

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## #39 2006-12-19 01:29:04

luca-deltodesco
Member
Registered: 2006-05-05
Posts: 1,470

### Re: Mental arithmetic making you look bad?

for 12x12 i got average of 1.4s

for the double minus one i got 2.4s
for the double add one i got 0.9s

The Beginning Of All Things To End.
The End Of All Things To Come.

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## #40 2006-12-19 01:50:23

Toast
Real Member
Registered: 2006-10-08
Posts: 1,321

### Re: Mental arithmetic making you look bad?

Thanks mathsyperson, it's working ok now.

It's Genius MathsIsFun, Nobel Prize! I can see myself playing this every day. This is a great way to help kids with their arithmetic. It's addictive, not overly complex, and helps me identify my strengths and weaknesses.

Ya know, a brilliant way to encourage use of this excellent game would be to enable multiplayer play, this can involve arithmetic races, relays etc. It could become big .

Oh yeah, btw my scores so far with 10 q. and no incorrects :
+1: 0.677, +2: 1.640, -1: 0.893, -2: 3.318, 5*5: 0.703, 10*10: 0.867, 12*12: 0.784

Last edited by Toast (2006-12-19 01:53:01)

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## #41 2006-12-19 05:26:44

mikau
Member
Registered: 2005-08-22
Posts: 1,504

### Re: Mental arithmetic making you look bad?

luca-deltodesco wrote:

for 12x12 i got average of 1.4s

for the double minus one i got 2.4s
for the double add one i got 0.9s

holy smokes... thats pretty good. I average like 10 seconds for the double subtraciton.

Like I said, my arithmetic needs work.

Last edited by mikau (2006-12-19 05:27:07)

A logarithm is just a misspelled algorithm.

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## #42 2006-12-19 07:40:44

Devantè
Real Member
Registered: 2006-07-14
Posts: 6,400

### Re: Mental arithmetic making you look bad?

MathsIsFun wrote:

OK. I have a version of Reaction Math for you to try out.

I can do "Add Single" with an average under 1 second. Beat that. Then have a go at 10x10.

It said 7x8, and I put 56. It said I was wrong for some reason.

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## #43 2006-12-19 07:44:49

Devantè
Real Member
Registered: 2006-07-14
Posts: 6,400

### Re: Mental arithmetic making you look bad?

Something a little wrong with this game...keeps saying I'm wrong.

First try on 12x12 :: 1.147 average seconds. I'll work on it.

Second try :: 1.103 s.

2.003 seconds on average for the double subtract. ^_^

1.912 for double subtract.

Last edited by Devanté (2006-12-19 07:58:00)

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## #44 2006-12-19 08:25:43

Devantè
Real Member
Registered: 2006-07-14
Posts: 6,400

### Re: Mental arithmetic making you look bad?

Got 1.635 for double subtraction.

But it says 9 out of 10 because my finger slipped on the last question. I ended up putting 67 instead of 57. :'(

Last edited by Devanté (2006-12-19 08:33:45)

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## #45 2006-12-19 09:23:01

LQ
Real Member
Registered: 2006-12-04
Posts: 1,285

### Re: Mental arithmetic making you look bad?

You guys are so awesome! This is great. Add this to games if you haven't allready...

I see clearly now, the universe have the black dots, Thus I am on my way of inventing this remedy...

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## #46 2006-12-19 11:17:43

John E. Franklin
Member
Registered: 2005-08-29
Posts: 3,588

### Re: Mental arithmetic making you look bad?

Very nice software indeed!! Much enjoying.
Also Mikau could try the ../games/flippa-memory-game.html
where .. means go back one directory from the forum.

igloo myrtilles fourmis

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## #47 2006-12-19 12:03:24

MathsIsFun
Registered: 2005-01-21
Posts: 7,684

### Re: Mental arithmetic making you look bad?

Wow, glad you like it, and thanks for the very nice compliments! (blush)

I will modify it to ignore the enter key ... this is why it is SO good that you tell me what happens.

=========

I am now thinking that a "Multiplication Trainer" would be a good idea for younger members. My idea is to keep track of performance, and suggest strategies for improvement.

So, what mental strategies do you use in multiplication?

This is my list (up to 10×):

a×b=b×a, so only have to remember about half the table

2×: just double (actually use your memory because for example 2×6=12 is easy)
5×: half of 10×
9×: "tens" is number-1, "units" is 10-number, up to 9×9 (e×ample: 9×5 = [5-1][10-5] = 45)

Then memory for everything else:

Small numbers: 3×3=9, 3×4=12, 4×4=16 (easy to remember)
Bigger numbers (where you need to practice to remember):
3×6=18, 3×7=21, 3×8=24
4×6=24, 4×7=28, 4×8=32
6×6=36, 6×7=42, 6×8=48
7×7=49, 7×8=56
8×8=64

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

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## #48 2006-12-19 12:18:07

mathsyperson
Moderator
Registered: 2005-06-22
Posts: 4,900

### Re: Mental arithmetic making you look bad?

I find that I just know all the multiples up to 10x10. I never actually memorised them properly, but as you use them so often while doing other things you tend to just learn them anyway.

Why did the vector cross the road?
It wanted to be normal.

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## #49 2006-12-19 19:08:44

Toast
Real Member
Registered: 2006-10-08
Posts: 1,321

### Re: Mental arithmetic making you look bad?

At my school we learnt the multiplication to 12*12 in grade 3. Hmmm, there was this guy who could recite the 6 times tables in 7 seconds o_O, yeah, I'm glad we had those multiplication races.

Another strategy I use a lot is multiplication by parts:
16*65 = 10*65+6*65 = 10*5+10*60+6*60+6*5

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## #50 2006-12-19 19:24:55

Devantè
Real Member
Registered: 2006-07-14
Posts: 6,400

### Re: Mental arithmetic making you look bad?

People often give me stupid things to work out in my head and they'd give me 5-15 seconds to work it out. If it was simple, like 537x7, I'd easily just do:

(537×10)-(537x3)

= 5370-1611
= 3759

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