This self-checking resource contains one google slides activity/game about finding area of a circle. The activity contains 12 questions (6 with radius and 6 with diameter) and will instantly provide feedback to students. If students get the question correct it takes them to another slide that tells them it is correct and then directs them to the next question. If students get the question wrong then it takes them to another slide that tells them it is incorrect and then directs them back to the question to keep trying.

I have my students get out a separate sheet of paper and show work on the paper if using it as an assignment.