spring 2026

math 113 · discrete structures

Counting, graphs, recursion, and number theory — a first course in reading and writing mathematics.

syllabus: Syllabus
textbook: Discrete Structures by Ormsby & Perkinson
discussion: Zulip
submissions: Gradescope
meetings: S01: MWF 10-10:50 in Lib 389
S02: MWF 12-12:50 in Chem 301
office hours: Tu 13-14, Th 14:30-15:30 in Lib 306
scheduling: Scheduling link
course assistant: Vivek Malik
problem session: TuTh 18-19 in Lib 204
drop-in tutoring: SuMWTh 19-21 in Lib 204
absence form: Absence form
homework extension form: Homework extension form

- review session Th 1:30-2:20pm in Lib 389 - usual office hours (Tu 1-2pm & Th 2:30-3:30pm)

jump to this week ↓41 meetings

week 1

mon jan 26

in classworksheet
assignedhomework due January 30

wed jan 28

lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due February 2
notesyllabus❦reading mathematics❦beginning counting (pp.9-13)

fri jan 30

readingthe language of sets pp. 14–18
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due February 4
duehomework by 10pm

week 2

mon feb 2

readingadditive and multiplicative counting pp. 19–22
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due February 6
duehomework by 10pm

wed feb 4

reading[writing mathematics](/files/113spring26/writing.pdf)
assignedhomework due February 9
duehomework
notein class: writing workshop

fri feb 6

readingfunctions pp. 23–30
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due February 11
duehomework by 10pm

week 3

mon feb 9

readingpermutations and combinations pp. 31–34
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due February 13
duehomework by 10pm

wed feb 11

readingequivalence relations pp. 35–39
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due February 16
duehomework by 10pm

fri feb 13

readingAl-Karaji's (Pascal's) triangle and the binomial theorem pp. 40–45
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due February 20
duehomework by 10pm

week 4

mon feb 16review

duehomework by 10pm
notereview❦exam instructions❦practice exam❦contact me by Sunday February 15 if there are problems you want to review

wed feb 18exam

notein-class exam❦exam instructions❦practice exam

fri feb 20

readinginduction pp. 46–50
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due February 25
duehomework by 10pm

week 5

mon feb 23

readinginclusion/exclusion pp. 51–55
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due February 27

wed feb 25

readingpigeonhole principle pp. 56–57
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due March 2
duehomework

fri feb 27

readinggraph theory - vertices, edges, degrees pp. 81–84
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due March 4
duehomework

week 6

mon mar 2

readingpaths and cycles pp. 85–90
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due March 6
duehomework
notesubmit exam revision

wed mar 4

readingtrees pp. 91–97
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due March 9
duehomework

fri mar 6

readingCatalan structures pp. 101–105
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due March 13
duehomework

week 7

mon mar 9review

duehomework by 10pm
notereview❦exam instructions❦practice exam❦contact me by Sunday March 8 if there are problems you want to review

wed mar 11exam

notein-class exam❦exam instructions❦practice exam

fri mar 13

readingfull binary trees and parenthesizations of binary operators pp. 106–109
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due March 18
duehomework by 10pm

week 8

mon mar 16no class

wed mar 18

readingrecurrence relations and difference operators pp. 58–64
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due March 30
duehomework by 10pm

fri mar 20

readingintroduction to generating functions pp. 65–68
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due April 1

spring break

March 21-29

noteno class

week 9

mon mar 30

readingprobability spaces pp. 127–130
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due April 3
duehomework by 10pm
notesubmit exam revisions by 10pm

wed apr 1

readingindependence pp. 131–133
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due April 6
duehomework by 10pm

fri apr 3

readingconditional probability pp. 134–136
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due April 8
duehomework by 10pm

week 10

mon apr 6

readingexpected value pp. 137–140
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due April 10
duehomework by 10pm

wed apr 8

readingBernoulli, binomial, indicator, and geometric random variables pp. 141–143
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due April 13
duehomework by 10pm

fri apr 10

readingdivisibility and primes pp. 149–152
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due April 15
duehomework by 10pm

week 11

mon apr 13

readingdistribution of primes pp. 153–156
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due April 20
duehomework by 10pm

wed apr 15review

duehomework by 10pm
notereview❦exam instructions❦practice exam❦contact me by Tuesday April 14 if there are problems you want to review

fri apr 17exam

notein-class exam❦exam instructions❦practice exam

week 12

mon apr 20

readingFermat's little theorem pp. 157–158
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due April 24
duehomework by 10pm

wed apr 22

readingEuclidean algorithm pp. 159–163
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due April 27

fri apr 24

readingmodular arithmetic pp. 165–170
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due April 29
duehomework by 10pm

week 13

mon apr 27

readingmodular units and Euler's totient function pp. 171–174
lecturelecture and quiz before class
in classworksheet❦solutions
assignedhomework due May 1
duehomework by 10pm
notesubmit exam revision

wed apr 29

readingSunzi's theorem pp. 175–177
lecturelecture and quiz before class
in classworksheet❦solutions
duehomework by 10pm
notepractice homework (not collected)

fri may 1

duehomework by 10pm
noteno reading❦no lecture❦course evaluations❦bring your laptop or tablet❦something REALLY fun

finals week

tue may 12final

notefinal exam 6-8pm in Bio 19 (both sections)❦exam instructions❦practice exam