In “Homework Guidelines”, Elizabeth Stapel wrote,

Mathematics is a language, and as such it has standards of writing which should be observed. In a writing class, one must respect the rules of grammar and punctuation, one must write in organized paragraphs built with complete sentences, and the final draft must be a neat paper with a title. Similarly, there are certain standards for mathematics assignments.

This article is worth reading in general. Here is the list of what I think is essential to write a mathematics homework.

- Write the assignment number and your last name initial with a dot in between at the right top corner of the first page. Below them, write the course number followed by your name.
- Clearly indicate the number of the exercise you are doing.
- Do “scratch work” on scratch paper. Hand in only the “final draft”.
- Show your work in the shortest and neatest way that you can think. Meanwhile, show your steps and explain your reasoning.
- End your proof in a fashionable way. Use QED or \blacksquare (blacksquare) to indicate end of a proof.
- Use sufficient space for each problem. Leave at least one blank line or draw a horizontal line between one problem and the next.
- Attach your pages with a paper clip or staple.

This is a working example for Assignment A. Suppose the student is enrolled in 21-600 whose name is the same as TA’s.