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## #1 2006-06-12 11:00:10

WD
Member
Registered: 2006-06-12
Posts: 3

### Embarrassing but I need simple help

First of all, hello one and all.

I am twenty years old and my numeracy skills are appalling. Maths was always a weak subject for me back in school, and because my school days weren't exactly pleasant (don't worry it won't be a long-winded life story ) I lost all concentration and interest in Mathematics full stop.

Even my simple times table are atrocious and I don't know why. I struggle with the 7 onwards times table. Not to mention my inability at simple sums. For example: Your average person my age, or even a lot younger, if asked 7 x 8 will instantly know the answer is 56, but I will struggle and take more than the usual time.

I've got a Mathematics book for beginners but even reading that isn't seeming to help me.

Does anyone know the root to the problem? Or am I just naturally inept at Maths?

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## #2 2006-06-12 13:15:30

Ricky
Moderator
Registered: 2005-12-04
Posts: 3,791

### Re: Embarrassing but I need simple help

For the times table, it's just simple memorization.  Just keep practicing, and you'll get it.

For addition, there are tricks you can use to add faster.  For example, when you do 16 + 94, what I see is that I can take 6 away from 16, and then add 10 to 100 to get 110.  To me, this is easier.  To others, it may make things more complicated.

"In the real world, this would be a problem.  But in mathematics, we can just define a place where this problem doesn't exist.  So we'll go ahead and do that now..."

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## #3 2006-06-12 14:45:46

MathsIsFun
Registered: 2005-01-21
Posts: 7,659

### Re: Embarrassing but I need simple help

Yep, the times table is special - it requires plain old memory, plus there are a few tricks: Multiplication - Times Tables

If you are having trouble elsewhere there *may* be a root cause - at some stage you may have failed to understand something, and then everything else you tried to build on those shaky foundations became just plain confusing.

Why not try some of the pages on this site, starting here: Elementary Math

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

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## #4 2006-06-14 03:15:49

WD
Member
Registered: 2006-06-12
Posts: 3

### Re: Embarrassing but I need simple help

Thank you both for your help.

I shall follow the link provided and try to improve my times table, plus other simple levels of mathematics.

I'll return if I need anymore help/tips etc.

Thanks again

Last edited by WD (2006-06-14 03:16:02)

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## #5 2006-06-14 04:22:05

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

### Re: Embarrassing but I need simple help

If you read the different pages here on mathsisfun, you should be taken trough alot of the basic math. What has helped me alot throughout my school time, has been to ask. Don't ever feel embarrassed to ask(you've already made this post, so shouldn't be a problem) a question if you're in doubt. Doesn't matter if you're 7 or 70, you'll always be able to get help here.

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## #6 2006-06-14 06:26:56

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

### Re: Embarrassing but I need simple help

I was trying to make times tables easier with poems, but I think we kind of failed miserably.
See them here: http://www.mathsisfun.com/forum/viewtopic.php?id=2903

Did you notice an odd number times an odd number is always an odd number?

7x7=49  8x8=64  9x9=81
8x6=48  9x7=63
9x6=54  9x5=45

igloo myrtilles fourmis

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## #7 2006-06-14 07:47:48

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

### Re: Embarrassing but I need simple help

Click on picture to see it bigger.

igloo myrtilles fourmis

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## #8 2006-06-14 08:37:56

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

### Re: Embarrassing but I need simple help

John - never thought about it like that, but I think your method is confusing if you don't know the time tables already, and you're not that good at math in general.

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## #9 2006-06-14 08:58:38

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

### Re: Embarrassing but I need simple help

He needs help qwabove 7, so I thought this would help.  But he said he is bad at small sums, so maybe not, but this will give him a lot of practice!  qwabove means equal and above.

igloo myrtilles fourmis

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## #10 2006-06-14 10:30:48

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

### Re: Embarrassing but I need simple help

Trachtenberg came up with this during WWII.
http://www.pagalguy.com/forum/prep-reso … metic.html

igloo myrtilles fourmis

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## #11 2006-06-14 12:52:06

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

### Re: Embarrassing but I need simple help

Here are my notes for the times tables after I read about J. Trachtenberg.

50% means half
10% means take off the zero on the end, so 70 becomes 7, for example.

3 x 3
30% of 30
OR 50% of 30 minus 10% of 30 minus 10% of 30
OR half of 30 minus 3 minus 3
OR 3 + 3 + 3
OR 30/3 - 3/3

3 x 4
4 + 4 + 4
OR 30% of 40
OR 50% of 40 minus 10% of 40 minus 10% of 40
OR half of 40 minus 4 minus 4
OR half of 30 minus 3
OR 40/3 - 4/3

5 x 3
50% of 30
OR half of 30
OR 50/3 - 5/3

5 x 4
half of 40

5 x 8
half of 80

5 x 5
half of 50

6 x 5
5 plus half of 50
OR half of 60

6 x 6
6 plus half of 60

7 x 6
7 plus half of 70
OR 6 plus 6 plus half of 60

8 x 6
8 plus half of 80.
OR 60 minus 6 minus 6

9 x 6
9 plus half of 90.
OR 60 minus 6

7 x 8
half of 80 plus 8 plus 8
OR 70 minus 7 minus 7

I think of 7 x 8 as 70% of 80 or 50% of 80 plus 8 plus 8.
I think of 8 x 7 as 80% of 70 or 100% of 70 minus 7 minus 7.
I think of 6 x 4 as 60% of 40 or 50% of 40 plus 4.

7 x 9
90% of 70
OR 70 minus 7
OR 70% of 90
OR half of 90 plus 9 plus 9

igloo myrtilles fourmis

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## #12 2006-06-17 05:15:31

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

### Re: Embarrassing but I need simple help

fourteen or bigger works!!!

7 x 7 is forty-something because 7+7 is fourteen.

7 x 8 is fifty-something because 7 + 8 is fifteen.

7 x 9 is sixty-something because 7 + 9 is sixteen.

8 x 8 is sixty-something because 8 + 8 is sixteen.

8 x 9 is seventy-something because 8+9 is seventeen.

9 x 9 is eighty-something because 9 + 9 is eighteen.

If it's 13 or less it doesn't work all the time, so just use this for 14 to 18.

igloo myrtilles fourmis

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## #13 2006-06-17 05:20:01

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

### Re: Embarrassing but I need simple help

Oh yeah, and

6 x 8 is forty-something because 6+8 is fourteen.

5 x 9 is forty-something because 5+9 is fourteen.

So fourteen and up only is the safest rule to go by that's easy to remember.

igloo myrtilles fourmis

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## #14 2006-06-17 12:53:52

MathsIsFun
Registered: 2005-01-21
Posts: 7,659

### Re: Embarrassing but I need simple help

John E. Franklin wrote:

Click on picture to see it bigger.

That is a clever way to illustrate it.

It works because 7×8 = (4+3)(4+4) = 4×4+4×4+4×4+3×4

And it works generally, so 7×8 = (4+3)(5+3) = 4×5+4×3+3×5+3×3

And could be useful when multiplying bigger numbers, too!

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

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## #15 2006-06-18 13:57:10

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

### Re: Embarrassing but I need simple help

Let's find 8 x 7 a fun way...
8 + 7 is fifteen (>=14) so fifty-something.
fifty-what??
Well 8 and 7 are 2 and 3 away from 10 and 2 x 3 = 6, so fifty-six!!  8 x 7 is 56.

Let's do another one.
9 x 3...  So 9 + 3 is 12, darn (too bad) 12 < 14 so can't do this one with the 14-up method.
However 9 x 3 ends in a 7 because 9 and 3 are 1 and 7 away from ten and 1x7 is 7.

Let's do another one.
What's 8 x 8??   8+8 is sixteen, so sixty-something and 8 and 8 are 2 and 2 away from 10 and 2x2 is 4, so 64!!!

Pretty fun, huh?

igloo myrtilles fourmis

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## #16 2006-06-21 11:17:55

WD
Member
Registered: 2006-06-12
Posts: 3

### Re: Embarrassing but I need simple help

Thanks a lot to the further input, John E. Franklin in particular, much appreciated. I will certainly look into those tricks you have provided. And any further input from anyone is more than welcome.

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## #17 2006-06-22 16:54:16

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

### Re: Embarrassing but I need simple help

igloo myrtilles fourmis

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## #18 2006-06-22 17:59:15

MathsIsFun
Registered: 2005-01-21
Posts: 7,659

### Re: Embarrassing but I need simple help

Kudos to John

And good work all of us "not" in particulars.

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

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