"Problems to look at" are not to be turned in if they're not extra credit problems.

Keep "file" problems in a file for occasional inspection.

Turn in "assigned problems" on the given due date at the start of class.

Homework rules

Students are encouraged to discuss course topics with one another. On assigned work, though, you are expected to do the work on your own. Your discussion with other students should be confined to matters related to understanding the problems and general approaches to doing problems, and you should acknowledge those who help you in this way. You should not collaborate on problem solutions unless directed otherwise.

• Acknowledge your sources (people and texts).
• In nontrivial problems, show how you get your answers.
• Turn in neat, well-written solutions, not messy first drafts. Trim "fringes." Staple multiple-page submissions.
• Do not copy collaborative solutions; write up solutions in your own words.
• Turn in homework on time. Each class day late reduces the possible points by 33%.
• Do extra credit problems entirely on your own. Turn in solutions separately from regular homework.