They all start with 8.0...after that the lowest is 8.008 - it has 0 affter this,
8.008,
then 8.08 and 8.081, both have 8 after this, and the first one is lower (it's equivalent to 8.080)
so:
8.008, 8.08, 8.081
finally, the last number, which is the biggest,
The answer: 8.008, 8.08, 8.081, 8.09