[We] mention the request for rain {lit. "Strength of the Rains"; ref. to the short prayer Mashiv Haruach} in [the blessing of] Techiyat Hameitim (Resurrection of the dead);
and [we] ask for rain [by adding the phrase V'tein tal umatar l'vracha] in Birkat Hashanim (Blessing of the year's crops);
and [we recite] Havdalah (Separation between sacred and mundane) in [the blessing of] Chonein Hadaat (Imbuer of knowledge).
Rabbi Akiva says:
One recites [Havdalah] as a fourth blessing by itself [before Chonein Hadaat].
Rabbi Eliezer says:
[One recites Havdalah] in the blessing of Modim (Thanksgiving).