The project addresses a "problem", e.g., what is the cheapest possible diet I can eat and still be healthy?, what is the best path to take on a trip of multiple cities?, etc.
Describe what you will be modeling and what mathematical concepts you will primarily be incorporating (e.g., linear programs, graphs, markov chains, etc.)
Describe how you came upon this problem.
Give history of similar and related problems.
Give the mathematical model you have developed for your investigation.
Present any calculations, describing all methods used, including all code, R commands, etc.
What did you find out? What do your model and calculations tell you?
Modify your problem in at least two different ways, analyze how your model needs to be updated, and find solutions to these problem variations. What do these variations tell you?
What are the major conclusions you can make from your efforts?
Cite all sources of quoted material.
Take a look at the Chicago Manual of Style's citation guidelines for ideas of how to cite well.
Note: if you are citing a web source, you must include the URL. If the URL is ridiculously long, feel free to truncate it, but only do so if necessary.
Feel free to put long tables, code, output, etc., in appendices, but be sure to describe and label them well so that one can read them on their own without having to refer back to the rest of the paper.