New to CM method. How to grade each subject?

Hi, We are very new to the CM method.  My children are 5th and 7th graders.  Can you tell me how you keep grades? I know how with math and grammar.  It’s all the rest that I am concerned with.  With narration, dictation, and others I’m not sure how to put a grade to it.  Also, do you give test for subjects like history and science? TIA!