Answer :

I don't know which digit do you mean, but it's not a problem to take a look at the whole number:

2.195

2 is for thousands
1 is for hundreds
9 is for tens
5 is for ones

Unless you meant 2.195 as a decimal (not a whole number - two thousand and one hundred ninety five), then:

2 is for ones
1 is for oneths
9 is for tenths
5 is for hundredths

In both situations each place has a 10 times stronger value than the digit to its right.