I sent my daughter for a year, thinking it was an ordinary pre school. I was wrong. She learned the continents, and could accurately put them together into a world map.
She snuck up to my FIL’s apartment, a granny flat upstairs from our house. She wasn’t supposed to be there, but she found his dry erase board and wrote “Becky have been op here”.
Spelling aside, she was reading and writing, and she was barely four years old!
And then I sent her to public school kindergarten. In that environment, she unlearned everything she knew. She stopped reading and writing, and didn’t pick it up again until about the second grade. The public school methods were entirely different. Not as good. If I had it to do over, I would have left her in Montessory through the first grade. By then, reading would have been second nature to her, and they would only care that she entered second grade as a strong reader.