How do I express as a variable if it's not on the screen?

Suppose we have screen 1, screen 2, and screen 3

What if I want to give 5 points for screen 1, 10 points for screen 2, 0 points for screen 3?

How can I represent the screen the user is currently on?

You can store values in variables. If you want to keep track of the screen, just set a variable to the text string “screen 1” or “screen 2” etc.

If you want to learn more about variables, Google variables Thunkable. The first result is usually the documentation.