Bell test (Earth-2356)

The bell test was a form of examination that was given to the Jedi younglings. The Jedi Master who had been assigned to test out the three-man cell used this test to determine whether the three students are worthy of being officially promoted into Padawan, sent back to the Jedi Temple for further training.

History
When Jedi Master Yoda performed this test on his students, both Orochimaru and Tsunade managed to take the bells, while Jiraiya did not and was tied up to a stake as punishment.

When Obi-Wan Kenobi performed it years later on Anakin Skywalker, Sasuke Uchiha, and Sakura Haruno in the Third Training Ground, he forbade any of them from eating breakfast beforehand, and that whoever failed to get a bell would not get lunch either, and instead would be tied to the stake and watch the others eat. None of his students were able to take it due to their refusal to work together, with Anakin even caught trying to eat the lunch sneakingly. Obi-Wan nearly expelled all three from the training ground for their lack of teamwork, but they redeemed themselves by breaking his order of not to feed Anakin, showing team spirit.

Three and a half years after Team 7 was formed, Obi-Wan once again performed the bell test on his students to evaluate their improvement, but since Sasuke had defected from the Jedi Order, Anakin and Sakura needed only to take a bell each. Having trouble defeating Obi-Wan despite their improvements, they resorted to threatening to spoil the ending of Obi-Wan's favourite novel series, Icha Icha, and then each took a bell for themselves while he was distracted.

Details
The test was for the each student to take one of the two bells from their to-be teacher within a set time limit in order to pass. Since there were three students, it would seem that one of them will be sent back to training no matter what. This, however, is a ruse to test out whether the three can work as a team: if they ignore the fact that only two bells are available and be willing to work together, they might have enough skills to take the bells, and be allowed to pass. Because the Jedi Master were too strong for the younling to beat in any way, shape, or form, the true test is the youngling's ability to work as a team and as such, the Master has to give them just enough allowance so they can't obtain the bell without teamwork. One exception to this test was Anakin and Sakura being tested by Obi-Wan since they each were trained by a Sannin, Obi-Wan had to fight seriously to not only test their teamwork but their actual skills.

Source

 * https://naruto.fandom.com/wiki/Bell_Test.