Psyche's ancestral magical mind reading. Why is it so accurate?

The rules of the play are as follows:

Choose one or two digits at will (or? Choose any number between and 99), add the ten digits of this number to the four digits, and then subtract this sum from any selected number. For example, the number you choose is 23, then 2+3=5, and then 23-5=18.

Find the figure corresponding to the final number in the chart, keep this figure in mind, and then click the crystal ball. You will find that the figure displayed by the crystal ball is the one you just memorized in your mind.

In fact, this game had an html version a long time ago, but now it has just been replaced by a flash version. The whole secret of the game lies in two points. One is the special calculation method. The second is this symbol lookup table.

the first point can be explained by simple algebra. Any two-digit number can be abbreviated as 1*A+B, where (a and b are both single digits). For example, 23 in the example is 1*2+3. Then subtract the sum of the digits from this number, which is expressed by algebra as 1*A+B-(A+B), and combine the similar items, and the result is 9*A, that is, no matter what two digits you come up with, after calculating according to his method, the result is 9*A, that is, the result can only be multiples of 9, 9, 18, 27, 36 ... Therefore, in FLASH, just make sure that the symbols represented by these numbers are consistent. But some people say that if this is the case, the results of each query will be different. The secret lies in this query table. In fact, this table is different every time, and it has changed secretly without knowing it. Some people claim that this is a gypsy mind-reading, but because this watch has to change all the time, the game can't be played in the traditional way unless it is through a computer. This is also a computer-specific mind reading.