Number between 3.09 and 3.1

To find such a number, you can write anything at the end of the smaller number (this works only because it's decimal fraction): this number will then be bigger than the first one, you just need to make sure this number is smaller than the other one.

Some examples:

3.0903
3.090303
3.0989898909
3.0922222222222222

5025 would be the answer