Question: "join" used in the same way in the following two sentences?

Many children join a sports club.

He joined the Communist Party as a young man.
Answer: the same meaning
Question: "care" used in the same way in the following two sentences?

He doesn't care about how / whether she comes.

I don't care what he does.
Answer: the same meaning
Question: "unit" used in the same way in the following two sentences?

Change per unit volume.

He was a member of a special police unit.
Answer: different meanings
Question: "credit" used in the same way in the following two sentences?

He arrived five minutes late, but to his credit he did work an extra ten minutes at the end of his shift.

He was given credit for his work.
Answer:
the same meaning