Which number is closest to 0.1?

The integer/whole number closet to 0.1 is zero. If you can use decimal numbers, you will always be able to come up with a number closer to 0.1 than anyother number (exept 0.1 itself). For example 0.100000001 is very close to 0.1, but 0.10000000000000001 is even closer.