How is it done!!

[Chris]

Work out how this is done without cheating and looking up on a search engine.. :)

spooky.... but safe site...


www.milaadesign.com/wizardy.html

Click and paste the link !!

[NigelS]

I could spoil it for you by telling you how it works...neat little trick though

[H]

Having dabled in a degree level mathematics im with nige...but i wont spoil it for everyone else :D

I'll have a go at answering it.

I have prepared a selection of three possible sums, thus :
54-(5+4=)9=45; 84-(8+4=)12=72; 67-(6+7=)13=54.

If you look for a relationship between 45, 72 and 54 you will note that they are all divisible by 9. This will apply for whichever two digits you happen to pick.

Now I took a print of the grid and am looking at it now, and see that 45, 72 and 54 all have the same symbol. But if I look at the grid again, the next time they have changed to a new symbol.

So the answer is the 'nine progression' plus symbols that shift across after each go, giving you a 'symbol of the moment' while you think that it's being very clever and reading your mind.

I twigged this by not bothering to do a calculation, and still getting a symbol ! :o

[JB]

Sussed it but wont let on how its done.

[SirKT]

And there i was thinking we had a brilliant computer :P

[BB Warrior]

Very simple...... but very clever! ;D

Which makes it 50% like me then........ :o ::)

[Chris]

What can I say Tommo... you are a little star... ::)

Thanks Chris, it was a good find and both entertaining and stunning.

I have seen a similar trick with playing cards: it relies on you not noticing that the set of four court cards change each time they are displayed.

Got any more ? ;D

[H]

If you look at it algebraically (oh god here we go):

10x + y (where x is the first digit, and y is the second digit of our number) is a general form for our chosen number,

so:

(10x+y) - (x+y) = (10x - x) + (y-y) = 9x - 0 = 9x

Since x is an integer between 0 and 9, your solution is always going to be a multiple of 9!

[Chris]

You are both brill.... ;) as both answers are correct in their own right.
Being a Headteacher guess you both deserve a Gold Star !!!

When I get more like this will post them Tommo...