What is right?

Hi,

Let us say that K-11 stands for students in the eleventh grade. Let us also say that there are many students for that grade level and there are a system to distinguish those people like this: 11-1, 11-2. etc.

Typically, (the??) 11-1 class is consisted of 15 students.

How should I write this?

I am a student in 11-1 class. Or

I am a student in the 11-1 class.

And, normally, classes that are part of school curriculum are written without Engglish articles but how much can I extend that concept? Can it be extended to 'reading class' or 'writing class"?

I have math class in/on my third period.

I have (the??) reading class in/on my third period.

Also, It is known that 'math class' is normally used without articles, but can a situation be created where an indefinite article, 'a', is necessary like this?

Teacher's Aid: Hi, John, why are you doing Algebra problems in science class. Don't you know this is math class (a math class???)? Put away your papers.

John: Sorry, I will be more attentive to the lessons on hand.