Decrypt magic crystal Reader

My friend sent me a flash and said it was a magic mind-reading technique from the original rozias. It can test your inner feelings. Note:
Select a double digit (or, from 10 ~ Select a number between 99), add the ten digits of the number to the single digit, And then subtract the sum from the number. For example, if the number you selected is 23, then 2 + 3 = 5, then 23-5 = 18
Find the graph corresponding to the final number in the chart, remember the graph, and click the crystal ball. You will find that the figure shown in the crystal ball is the one you just wrote down in your mind.

At the beginning, I thought it was incredible. After several times, I found that each final number is a multiple of 9. In the game, all the symbols at the multiples of 9 are the same, the figure displayed in the crystal ball is actually the figure at the position multiple of 9, so you did not discuss it.