Try to explain, patiently analyze problems with them and find solutions. An exam can't decide fate, so there's no need to be discouraged. Summing up experience is king. Anyway, I had a similar experience, but my parents didn't say anything about me in the end, just told me to do my best. Later, in the face of the big exam, no one remembered those small mistakes, but they accumulated a lot of experience for the last battle. Come on.