I just want to make sure that my understanding of the following problem is correct:
Suppose we want to find how many non-isomorphic abelian groups there are of order $3^2\times 5^2\times 7^2$.
Then, since 3,5, and 7 are all prime, we know that the number of non-isomorphic abelian groups of this order will be $2^3=8$, since the number of partitions of 2 is just 2.
Further, if we consider another example, say $3^2\times 5^2\times 7^5$, then we know that there will be (2)(2)(7)=28 non-isomorphic abelian groups of this order because there are 7 partitions of 5. This is done via the Fundamental Theorem for Fin. Gen. Abelian groups.
Is this all correct?
This is correct. Partitions are the key to counting finite abelian groups.