Is these sentences are correct.

Although Mr. Blatt always mixes up the students’ names, people get the feeling he doesn’t care.
If being called by another name is embarrassing, it makes the students feel unimportant as well.

Same question as before. We need clarity on your instructions.

These are fine, given the instructions you posted above.

Yes, the sentences you provided are correct grammatically. However, there are a few improvements that can be made. Here are the revised sentences:

1. Although Mr. Blatt always mixes up the students' names, people get the feeling that he doesn't care.
- Revised: Even though Mr. Blatt consistently confuses the students' names, it gives people the impression that he lacks concern.

2. If being called by another name is embarrassing, it makes the students feel unimportant as well.
- Revised: When students are called by incorrect names, it not only embarrasses them but also diminishes their sense of importance.

To answer your question, the sentences are grammatically correct, but they can be refined for clarity and readability.