 # Frustrating

I can’t figure it out… Help http://digicc.com/fido/

Someone once explained this to me, sorry I can’t remember exactly. It is something to do with (I think) the fact that the 4 digit number you have less the zero is divisible by 9. Then the answer is the number that totals a product of 9. E.g. if you input 12 then the answer will be 6.

I used 1111 the first time so it didn’t work Clever game.

I want to play again but don’t know how. Maybe i have to restart the website link? I first try with 1234 but… find nothing

Don’t understand its logic, why can it guess exactly the number i have circled? Uhm I try 7865, then jumble up 8657. Then 8657-7865 = 792. I circled on number 2. And it guess correctly number 2. But try immediately step 3, input the number --> it guess wrongly ;D

big bean is absolutely right think of any 4 digit number as +1000*a+100*b+10*c+1*d rearranging the digits would give you +1000*b+100*c+10*a+1*d and any diiference between the two would give you a number thats divisible by 9 for ex = +990*b-900*b-90c in the above case and the divisibility test for 9 is that the sum of digits must be divisible by 9, so when you remove one digit from the output you can work back to find the answer

primitive 