What is the principle of calculating age with mobile phone number?

This is really reasonable. No matter what your mantissa is, you will find that the number calculated in the previous step is 2X 13 after subtracting your year of birth. In fact, this is to subtract your birth year from this year's year 20 13. This x is just a cover for adding to the percentile. You need to add 1764 to this question next year. Take a look. In the fifth step, all those with a tail number of 8 are 28 13, all those with a tail number of 9 are 29 13, all those with a tail number of 1 213, and so on, and all those with a tail number of X are 2x/kloc-0.