Can you figure out how this works?

Navek



Joined: 01/06/2008
Posts: 2656

Message Posted:
18/11/2008 19:29

1) Go to the link below. After reading each window, click on the boy in the lower right corner of the picture.



2) In the last window type in your answer in the white box using the keyboard (there is NO cursor).



3) Watch the paper in the boy's hand. You will be amazed . . and no, I don't know how it's done.



http://digicc.com/fido

The-Wicks


Joined: 27/05/2007
Posts: 2279

Message Posted:
18/11/2008 19:43

Navek- I'm impressed it's very clever.

P

PtePike



Joined: 20/05/2008
Posts: 2334

Message Posted:
18/11/2008 19:50

Last time I saw Fido Dido must have been on an 80s T-shirt saying "Spliff me up". I went for a three-digit number and it didn't work for me as I ended up with only one digit. Have I f***** up, or did I outsmart it...?

Treesy


Joined: 14/08/2008
Posts: 406

Message Posted:
18/11/2008 20:20

its something to do with the sum of the final 4 digits equaling 9





ie if u r left with 008 then must be 1 as 0+0+8+1 = 9

Treesy


Joined: 14/08/2008
Posts: 406

Message Posted:
18/11/2008 20:24

basically when u subtract the digits always add to 9



i.e if 99 9+9 = 18 but 1+ 8 = 9 reduced numbers this is called





and its always 9 so u can always guess missing number







ohhhhh im gooood

scampy



Joined: 15/01/2008
Posts: 982

Message Posted:
18/11/2008 20:27

That was good..............

elko2



Joined: 24/07/2007
Posts: 4400

Message Posted:
18/11/2008 20:40

Treesy,

Not as easy as that, can you eleborate please? For instance, if I type my answer as 70 or 88 how is it that the number I circled was 2? If you can explain those two examples then I will say that you have solved it. In the meantime, I will be working on it

ismet

Treesy


Joined: 14/08/2008
Posts: 406

Message Posted:
18/11/2008 20:47

if your answer is 70 then 7+0 = 7 so to make 9 you need 2 more so answer is 2



as 7 + 0 + 2 = 9



if your answer is 88 then 8+8=16 and 1+6 = 7 you need 2 more to make 9



as 8 + 8 + 2 = 18 and then 1 + 8 = 9





hope that makes sense

elko2



Joined: 24/07/2007
Posts: 4400

Message Posted:
18/11/2008 20:59

Now I know enough to play with someone and amaze but I have not come up with a full explanation.



Let us use three digits to start with. If after sub traction I get 270 and I circle 2, the result I type will be 70. 7 + 0 = 7 and we need 2 to complete to 9, hence the circled number is 9.



In another trial with three digits I got the result as 288 and if I circle 2 again, the remaining number that I have to type is 88 i.e. 8 + 8 = 16 which requires 2 to complete it to a multiple of 9, hence the cicled number was 2.



Wtith four digit example, if the result is say 856 and I circle 6, the result to type is 85 i.e.8+5=13 and that requires 6 to complete it to a multiple of 9, hence the circled number was 6.



Now we are ready to play and amaze people. The difficult thing was to create the problem rather than solve it. Nice one.

ismet

elko2



Joined: 24/07/2007
Posts: 4400

Message Posted:
18/11/2008 21:01

Treesy,

You were right, my apologies. I did not look at your answer colsely.

ismet

teatime


Joined: 20/10/2008
Posts: 852

Message Posted:
18/11/2008 21:02

Whst's all this about 9? My answer was 6.

Or am I being thick?

elko2



Joined: 24/07/2007
Posts: 4400

Message Posted:
18/11/2008 21:08

Teatime,

Oh dear dear, when you subtracted the two numbers and cicled one of them, what was the reamaining number? You tell us and we will tell you the number you circled? Is that ok?

ismet

Treesy


Joined: 14/08/2008
Posts: 406

Message Posted:
18/11/2008 21:13

Elko2



no probs - but what i cant explain at this moment is why it always equals 9 when u subtract same 4 digits but in different order - my brain remembers something about it from years back but cant think right now ------

teatime


Joined: 20/10/2008
Posts: 852

Message Posted:
18/11/2008 22:06

Elko2

408

rocky


Joined: 17/10/2007
Posts: 1749

Message Posted:
18/11/2008 22:09

who really cares

elko2



Joined: 24/07/2007
Posts: 4400

Message Posted:
18/11/2008 23:19

msg. 14

Teatime,

The number you circled was 6. 4+0+8= 12; 1+2=3, thus you need 6 to complete it to 9. As simple as that.

ismet

Groucho



Joined: 26/04/2008
Posts: 7993

Message Posted:
19/11/2008 07:51

So the mathematical rule is that for 3 or 4 digit numbers when you jumble them up and subtract the lesser from the greater the resulting number's digits when added up will always be a multiple of nine...



When you declare the non-circled numbers it is therefore easy to calculate the circled (hidden) digit as it is this one you would need to add to make a multiple of nine....

elko2



Joined: 24/07/2007
Posts: 4400

Message Posted:
19/11/2008 08:10

Exactly. QED

ismet

Skogsy


Joined: 15/05/2008
Posts: 339

Message Posted:
19/11/2008 08:28

Who has the lowest Erdős number then?



Skogsy

elko2



Joined: 24/07/2007
Posts: 4400

Message Posted:
19/11/2008 09:28

Of course Erdös himself

ismet

Groucho



Joined: 26/04/2008
Posts: 7993

Message Posted:
19/11/2008 14:22

Pike,



Indeed you managed to {expletive deleted} it up....



Didn't they do arithmetic at your borstal?

mustafa


Joined: 18/11/2008
Posts: 9

Message Posted:
19/11/2008 14:24

Very good,all my family are at it