The 3rd Grade Magic Test. A Piece of Cake for Doremi?
The girls go to take the Level 3 Exam, hoping to pass so they can be granted each a seedling that eventually sprouts into a tree and yields an endless supply of magic spheres. Surprisingly, the exam is one they will have to take separately. They each must pass through a door into their own world to encounter a series of events that will test their own individual strengths and are only allowed to use magic twice. The girls also must also complete the exam in one hour or else they will fail.
Aired 14/11/1999EP 40 - The 3rd Grade Magic Test. A Piece of Cake for Doremi?

Magical DoReMi
Doremi Harukaze, 3rd grade student at Misora Elementary School, claims to be the world's unluckiest pretty girl. Fascinated by witchcraft, she is drawn into a mysterious shop where she meets Majo Rika and is able to deduce that this lady is in fact a real witch. Being exposed by a human triggers a curse that transforms witches into magical frogs. To regain her original body, Rika must turn Doremi into a witch by teaching her how to use magic. Thrilled by this odd development, Harukaze becomes a witch apprentice. Unfortunately, her two best friends, Hazuki Fujiwara and Aiko Senoo, discover that Doremi has become a magic user. Afraid that Harukaze might become a magical frog too, Majo Rika recruits both Hazuki and Aiko and makes them witch apprentices too. The trio has lots of adventures as they try to triumph the necessary trials to become real witches.
(Source: Anime News Network)