Magic Hat number prediction trick

A friend just sent me this stuff I can’t understand how it works. Maybe somehow it detects where I am watching, but not sure, cause it doesn’t request camera permissions… Few hours I can’t figure out how it works, I know there is some trick and my friends won’t tell his secret. Please help me, smart people!

Ok good one, the trick is that it doesn’t matter the number you pick you always get the same symbol. Pick 50 and 45 will have the same symbol as if you picked 26 where 18 will have the same symbol, etc… For each run the symbol is fixed.

But before we digress, a more relevant question to this forum is , can you figure out a way to code this in javascript so that you get the same symbols placed all the time when you subtract the sum from the number you “thought” about ?

Dude, you are genius, a friend said that was AI, haha I feel so dumb now =)) I noticed that symbols are repeating itself every 9 numbers, so the code should be really simple. Something like that:

       var keySymbold = "$"


That’s right , but you don’t even need to get up to 90 for the criteria they set to be met, 81 suffices

Wow, I will send this code to my friend, maybe it will be useful for him! You are right, no need for 90. Thank you Derej!