Fall 2019: Intro to Number Theory (Math 311)


Instructor Dr. Armin Straub
MSPB 313
(251) 460-7262 (please use e-mail whenever possible)
Office hours TR, 9am-noon, or by appointment
Lecture TR, 4:30-5:45pm, in MSPB 345 (Section 502).
Midterm exams The tentative dates for our two midterm exams are:
Thursday, October 3
Tuesday, November 12
Final exam Tuesday, December 10 — 3:30pm-5:30pm
Text Elementary Number Theory,
by David M. Burton (McGraw Hill, 7th Ed., 2011)
Online grades USAonline
Syllabus syllabus.pdf

Lecture sketches and homework

To help you study for this class, I am posting lecture sketches. These are not a substitute for your personal lecture notes or coming to class (for instance, lots of details and motivation are not included in the sketches). I hope that they are useful to you for revisiting the material and for preparing for exams.

After most classes, homework is assigned and posted below.

  • You should aim to complete the problems right after class, and before the next class meets.
    A 15% penalty applies if homework is submitted after the posted due date.
  • Homework is submitted online, and you have an unlimited number of attempts. Only the best score is used for your grade.
    Most problems have a random component (which allows you to continue practicing throughout the semester without putting your scores at risk).
  • Collect a bonus point for each mathematical typo you find in the lecture notes (that is not yet fixed online), or by reporting mistakes in the homework system. Each bonus point is worth 1% towards a midterm exam.
    The homework system is written by myself in the hope that you find it beneficial. Please help make it as useful as possible by letting me know about any issues!
Date Sketch Homework
08/20 lecture01.pdf Homework will be assigned after next class.
Since this section was just created, this first lecture was an excursion. We will start fresh next class.
08/22 lecture02.pdf Homework Set 1: Problems 1-2 (due 9/5)
08/27 lecture03.pdf Homework Set 1: Problems 3-5 (due 9/5)
08/29 lecture04.pdf Homework Set 1: Problems 6-7 (due 9/5)
09/03 lecture05.pdf Homework Set 2: Problems 1-2 (due 9/19)
09/05 lecture06.pdf Homework Set 2: Problems 3-7 (due 9/19)
09/10 lecture07.pdf Homework Set 2: Problems 8-10 (due 9/19)
09/12 lecture08.pdf Homework Set 2: Problems 11-15 (due 9/19)
09/17 lecture09.pdf Homework Set 3: Problems 1-4 (due 10/3)
09/19 lecture10.pdf Homework Set 3: Problems 5-6 (due 10/3)
09/24 lecture11.pdf Homework Set 3: Problems 7-8 (due 10/3)
09/26 lecture12.pdf Homework Set 3: Problem 9 (due 10/3)
10/01 review get ready for the midterm:
complete the practice problems and all homework
10/08 lecture13.pdf Homework Set 4: Problems 1-4 (due 10/24)
10/15 lecture14.pdf Homework Set 4: Problems 5-8 (due 10/24)
10/17 lecture15.pdf Homework Set 4: Problems 9-12 (due 10/24)
10/22 lecture16.pdf Homework Set 5: Problems 1-3 (due 11/6)
10/24 lecture17.pdf Homework Set 5: Problem 4 (due 11/6)
10/29 lecture18.pdf Homework Set 5: Problem 5 (due 11/6)
10/31 lecture19.pdf Homework Set 6: Problems 1-3 (due 11/12)
11/05 lecture20.pdf Homework Set 6: Problem 4 (due 11/12)
11/07 review get ready for the midterm:
complete the practice problems and all homework
11/14 lecture21.pdf Homework Set 7: Problems 1-5 (due 12/3)
11/19 lecture22.pdf Homework Set 7: Problems 6-7 (due 12/3)
11/21 lecture23.pdf finish all homework
11/26 practice do the practice problems: final-practice.pdf
12/3 lecture24.pdf get ready for the final exam!
12/5 review get ready for the final exam!

Exams and practice material

The following material will help you prepare for the exams.

Quizzes and solutions

  1. quiz01.pdf, quiz01-solution.pdf
  2. quiz02.pdf, quiz02-solution.pdf


For more involved calculations, we will explore the open-source free computer algebra system Sage.

If you just want to run a handful quick computations (without saving your work), you can use the text box below.

A convenient way to use Sage more seriously is This free cloud service does not require you to install anything, and you can access your files and computations from any computer as long as you have internet. To do computations, once you are logged in and inside a project, you will need to create a "Sage notebook" as a new file.