0.09 in simplest form is 9/100
I write it as: 90 000 009 009 009 as I use the long scale (as used in Europe). Others write it as: 90 009 009 009 as they use the short scale (as used in USA).
009 = 9 is an integer and not a fraction. However, it can be expressed in rational form as 9/1. You can then calculate equivalent rational fractions if you multiply both, its numerator and denominator, by any non-zero integer.
nine thousandths
4+.2+.009
To write 2049.009 in word form, you would write "two thousand forty-nine and nine thousandths." The whole number part, 2049, is read as "two thousand forty-nine." The decimal part, .009, is read as "nine thousandths."