This is certain and proved, and there is no disappearing value in it!
The proof of 1 = 0.999 ... (Cycle) needs to use the limit. Here, we use two simple examples to illustrate the correctness of this relationship.
First, we know that 1/3 = 0.333...(3 cycles),
So 1/3× 3 = 0.333...(3 cycles )× 3,
And1/3x3 =1,
0.333 (3 cycles) × 3 = 0.999 (9 cycles),
So 1 = 0.999...(9 cycles).
Second, we know that 3÷3= 1.
However, if we deliberately calculate the quotient of 3÷3 in the vertical direction, then there will be more than 3 in the tenth place and only 9 more than 3 in the percentile; By the thousandth, the quotient will still be 9+3, and will continue to be 9+3 ... That is to say, the chamber of commerce will become 0.999...(9 cycles).
Therefore, 0.999...(9 cycles) is equal to 1, and there is no vanishing value.