No , you 're going the wrong way. It won't happen that all the numbers are 9 starting from a certain number.

This is easy to explain:

For example, 0.0099999 is actually 0.0 1, which is 0.0 1. So the situation of all 9' s in the back can be ignored.

If you have any questions, please ask. If you are satisfied, please click the "Adopt" button.