Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

Pages: **1**

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

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?

Thanks for your time

Offline

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

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..."

Offline

**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,626

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

Offline

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

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)*

Offline

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

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.

Support MathsIsFun.com by clicking on the banners.

What music do I listen to? Clicky click

Offline

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

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**

Offline

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

Click on picture to see it bigger.

**igloo** **myrtilles** **fourmis**

Offline

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

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.

Support MathsIsFun.com by clicking on the banners.

What music do I listen to? Clicky click

Offline

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

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**

Offline

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

Trachtenberg came up with this during WWII.

Click on link to follow:

http://www.pagalguy.com/forum/prep-reso … metic.html

**igloo** **myrtilles** **fourmis**

Offline

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

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**

Offline

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

fourteen or bigger works!!!

7 x 7 is **forty**-something because 7+7 is **four**teen.

7 x 8 is **fif**ty-something because 7 + 8 is **fif**teen.

7 x 9 is **sixt**y-something because 7 + 9 is **sixt**een.

8 x 8 is **sixt**y-something because 8 + 8 is **sixt**een.

8 x 9 is **sevent**y-something because 8+9 is **sevent**een.

9 x 9 is **eight**y-something because 9 + 9 is **eight**een.

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

**igloo** **myrtilles** **fourmis**

Offline

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

Oh yeah, and

6 x 8 is **fort**y-something because 6+8 is **fourt**een.

5 x 9 is **fort**y-something because 5+9 is **fourt**een.

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

**igloo** **myrtilles** **fourmis**

Offline

**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,626

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

Offline

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

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**

Offline

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

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.

Offline

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

@WD Glad I helped!!

**igloo** **myrtilles** **fourmis**

Offline

**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,626

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

Offline

Pages: **1**