* Officially, five wizards were sent to Middle-earth. These are the Istari, also known as the Wizards: Saruman, Gandalf, Radagast, and the two Blue Wizards.
* We only see Gandalf and Saruman in the books. Radagast has a minor role, and the Blue Wizards are only mentioned in passing. Their roles and activities are unclear.
* The number of "wizards" in Middle-earth is complex. The Istari were not the only beings with magical powers. There were also:
* Other Maiar: Some Maiar like Sauron chose to serve Morgoth, others remained in the world.
* Men with magical abilities: Like the Númenóreans, who practiced magic and eventually were corrupted by it.
Therefore, depending on what you consider a "wizard," the answer could be five, two (Gandalf and Saruman), or even many more.
It's important to remember that Tolkien's world is full of nuance and ambiguity. This makes it a rich and engaging world to explore, even if some details remain unclear.