What are the ways to level up?

Question

I don't understand why I went from level 9 to 12

Answer 1

You got alot of xp from a badge you got for completing 50 challenges.
The more xp you have, the higher your level

Answer 2

Participation. Almost anything you do gives xp. Completing lessons, doing challenges, getting upvotes, earning badges, etc...

Answer 3

Participation, the max in the challenge of XP Is 32

Answer 4

By unlocking badges, challenges and Completing three lessons in a day which eventually increase the levels or xps.

Answer 5

how to get morethan 3 heart