Is it possible to score student assignments manually?

Hi Alvin,

It is currently not possible to score student assignments manually through Khan Academy. 

You can, however, view the different answers of your students gave by viewing their score report if you'd like to record their scores differently outside of Khan Academy.

Once you're on the scores page, you can click on a student's score for a specific assignment. You'll be taken to the question bank(s) that were given where you'll be able to see their responses to the questions.

I hope this helps! Please let me know if you have any further questions.