English
posted by John .
1. My favorite class is a math class.
2. My favorite class is math class.
(Which one is right? are both OK? Do they have a different meaning?)
3. I have two math classes today.
4. I have two math class today.
(Which one is right?)

This is better:
2. My favorite class is math class.
This one is correct:
3. I have two math classes today.
Since you have TWO math classes, "classes" must be plural. 
If you're taking two math classes, then it would be more accurate to say "My favorite class is algebra (or geometry or trigonometry)."