Hi Katie,

The 9/10 means that 9 out of the 10 questions were answered correctly on the first try (the first answer submitted for the question). The red down arrow means that one of the skills (the one answered incorrectly) was leveled down. A skill (and possibly pre-requisite skills) will move down a level if a question associated with the skill is answered incorrectly.

You can learn more about this in the following articles:

• How can I understand my progress in Khan Academy?
• What are Course and Unit Mastery?

Let me know if you have any additional questions!