0.0001 is one ten thousandth as in "a micron is one ten thousandth of a centimeter."
0.001 is one thousandth, as in "a micron is one thousandth of a millimeter."
0.01 is one hundredth, as in "a penny is one hundredth of a dollar"
0.1 is one tenth, as in "I walked one tenth of mile"
In all the examples above, you can say a instead of one. "A micron is a ten thousandth of a centimeter."
10 is ten, as in "I owe you ten dollars"
100 is one hundred as in "I owe you one hundred dollars" Also can say "I owe you a hundred dollars".
Note that I wrote out "one". Writing "1 tenth" looks very odd.
Then there is the question of the hyphen. My preference is ten-thousandth, one-thousandth, one-hundredth, one-tenth, but I don't think it matters whether you use the hyphen or not, unless you have a style guide (or a teacher) which insists that you conform.