Just for a change of pace and a bit of fun I thought I would post this link.

It really works. See if you can figure out how.

http://www.mysticalball.com/

I must be thick.....fascinating,though!
I thought I had it cracked but my theory went out the window...come on....tell.......
Orla

Head hurts!!!!

If the first digit is x and the second digit is y then the maths gives the equation

10x + y - x - y = n

which simplifies to n = 9 x

In other words the multiples of 9 in the table all have the same symbol.

Nice reason for edit Posidrive.
On a more amazing note, Biiiiink has said on another thread that her school covered this in Primary 5!!! Fantastic.

Now all she has to do is discover the definition of fantastic. Hahahahaha.

Why not priamry 5? its really only addition and subtraction and looking at the patterns...a simple trick that would engage a smart child. No one said it was reduced to algebra or anything more advanced.

While you are putting the boot in, maybe I should point out that in another thread some mathematical genius stated with great certainty that there were "only 21 answers".

As (10x+y) was defined as >9 and <100, x has to be between 1 and 9, and therefore there are in fact only 9 possible solutions

Maybe people living in glass houses shouldnt throw stones

WW you said in another thread " respond to each new post as if I had never heard of the poster before. I don't hold grudges."

You seem to have contradicted your own high standards by having a go at Biiink in an unrelated thread.

Yes there are only 9 possible answers. My error. I must have been thinking of something else to do with playing with 9's. Such as 'Any number between 1 and 9 when multiplied by nine will give an answer whose 2 digits add up to 9' but 21 doesn't figure in that one either. The number 21 just popped out of my head from somewhere. Mea culpa.

As for putting the boot in. Why not. I give in response to what I get. Biiiiink seems to have taken it on herself to attempt to insult me. I have no problem with that.

Here's another boot. I don't believe she could actually explain how it works.

Regarding throwing stones. I don't live in a glass house.

No, I don't believe I have contradicted myself. The topic is the same as in the other thread. Therefore they are not unrelated. Thanks for noticing my standards are high.

It's very hard for sarcasm to come across sometimes in the written word

Really? I didn't notice.

Have a nice day.

Touche.... but then I genuinely hope you do have one.

Well, that took the "Fun" out of "Fun site for the day".

LOL thicker skin required Snave mate

Exactly Iain. A bit of end-of-term fun from an engaging teacher. That same lesson we also learned how to add all of the numbers from 1-100 together, and how to legitimately use "had" 12 times in a single sentence. You never forget useful stuff like that