LIVE 135: Combinatorics
W/F 12:00–1:30am from 6/19 (Your Time*)
This LIVE course contains a total of 30 hours of live video instruction (~$20/hour), plus 1 year of access to Prof. Loh's recorded videos from this course.
We’ve carefully designed our courses to maximize engagement. Each of our LIVE classrooms has at least one staff member for every 13 students. The typical class size is around 30 students.
* The official meeting time for this course is 8:00pm in New York.
Diagnostic Tests:
Calendar
Classes will meet on the highlighted dates. Click on any date to view the topics for that day.
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Lesson on new topic
Discuss homework challenge
Reviews
I fall asleep to prof. loh music every night and listen to his ted talk every night
We appreciate how much [our son] is learning and growing in this class. Thank you for making the world a better place through math and kindness!
I have high respect for Po-Shen, and was hoping for a while to get a first-hand view of this approach to online classes. [My daughter] didn't really let me observe too much, but she did confirm that this class was better than any other online classes she's had, and better than some in-person classes too. That's very impressive. Great job, everyone involved!
Thank you very much for explaining [my son's learning situation] in detail… I asked him about this course and he expressed that he was very interested and enjoyed learning this course. The school had a test for the most recent class, so I watched the replay in the afternoon. I think he gained something from this course. Thank you teacher!
[My daughter] enjoyed really much all the sessions she attended, thank you for the great teaching and animation!
u guys are my favorite pair of teachers
Tiring casework that is simplified by combinatorics class
Thanks so much for the detailed class participation summary! It is very helpful! [My daughter] said the class is very useful and more interactive activities than other virtual class she had before!
I fall asleep to prof. loh music every night and listen to his ted talk every night
We appreciate how much [our son] is learning and growing in this class. Thank you for making the world a better place through math and kindness!
I have high respect for Po-Shen, and was hoping for a while to get a first-hand view of this approach to online classes. [My daughter] didn't really let me observe too much, but she did confirm that this class was better than any other online classes she's had, and better than some in-person classes too. That's very impressive. Great job, everyone involved!
Thank you very much for explaining [my son's learning situation] in detail… I asked him about this course and he expressed that he was very interested and enjoyed learning this course. The school had a test for the most recent class, so I watched the replay in the afternoon. I think he gained something from this course. Thank you teacher!
[My daughter] enjoyed really much all the sessions she attended, thank you for the great teaching and animation!
u guys are my favorite pair of teachers
Tiring casework that is simplified by combinatorics class
Thanks so much for the detailed class participation summary! It is very helpful! [My daughter] said the class is very useful and more interactive activities than other virtual class she had before!
I fall asleep to prof. loh music every night and listen to his ted talk every night
We appreciate how much [our son] is learning and growing in this class. Thank you for making the world a better place through math and kindness!
I have high respect for Po-Shen, and was hoping for a while to get a first-hand view of this approach to online classes. [My daughter] didn't really let me observe too much, but she did confirm that this class was better than any other online classes she's had, and better than some in-person classes too. That's very impressive. Great job, everyone involved!
Thank you very much for explaining [my son's learning situation] in detail… I asked him about this course and he expressed that he was very interested and enjoyed learning this course. The school had a test for the most recent class, so I watched the replay in the afternoon. I think he gained something from this course. Thank you teacher!
[My daughter] enjoyed really much all the sessions she attended, thank you for the great teaching and animation!
u guys are my favorite pair of teachers
Tiring casework that is simplified by combinatorics class
Thanks so much for the detailed class participation summary! It is very helpful! [My daughter] said the class is very useful and more interactive activities than other virtual class she had before!
I fall asleep to prof. loh music every night and listen to his ted talk every night
We appreciate how much [our son] is learning and growing in this class. Thank you for making the world a better place through math and kindness!
I have high respect for Po-Shen, and was hoping for a while to get a first-hand view of this approach to online classes. [My daughter] didn't really let me observe too much, but she did confirm that this class was better than any other online classes she's had, and better than some in-person classes too. That's very impressive. Great job, everyone involved!
Thank you very much for explaining [my son's learning situation] in detail… I asked him about this course and he expressed that he was very interested and enjoyed learning this course. The school had a test for the most recent class, so I watched the replay in the afternoon. I think he gained something from this course. Thank you teacher!
[My daughter] enjoyed really much all the sessions she attended, thank you for the great teaching and animation!
u guys are my favorite pair of teachers
Tiring casework that is simplified by combinatorics class
Thanks so much for the detailed class participation summary! It is very helpful! [My daughter] said the class is very useful and more interactive activities than other virtual class she had before!
I fall asleep to prof. loh music every night and listen to his ted talk every night
We appreciate how much [our son] is learning and growing in this class. Thank you for making the world a better place through math and kindness!
I have high respect for Po-Shen, and was hoping for a while to get a first-hand view of this approach to online classes. [My daughter] didn't really let me observe too much, but she did confirm that this class was better than any other online classes she's had, and better than some in-person classes too. That's very impressive. Great job, everyone involved!
Thank you very much for explaining [my son's learning situation] in detail… I asked him about this course and he expressed that he was very interested and enjoyed learning this course. The school had a test for the most recent class, so I watched the replay in the afternoon. I think he gained something from this course. Thank you teacher!
[My daughter] enjoyed really much all the sessions she attended, thank you for the great teaching and animation!
u guys are my favorite pair of teachers
Tiring casework that is simplified by combinatorics class
Thanks so much for the detailed class participation summary! It is very helpful! [My daughter] said the class is very useful and more interactive activities than other virtual class she had before!
I fall asleep to prof. loh music every night and listen to his ted talk every night
We appreciate how much [our son] is learning and growing in this class. Thank you for making the world a better place through math and kindness!
I have high respect for Po-Shen, and was hoping for a while to get a first-hand view of this approach to online classes. [My daughter] didn't really let me observe too much, but she did confirm that this class was better than any other online classes she's had, and better than some in-person classes too. That's very impressive. Great job, everyone involved!
Thank you very much for explaining [my son's learning situation] in detail… I asked him about this course and he expressed that he was very interested and enjoyed learning this course. The school had a test for the most recent class, so I watched the replay in the afternoon. I think he gained something from this course. Thank you teacher!
[My daughter] enjoyed really much all the sessions she attended, thank you for the great teaching and animation!
u guys are my favorite pair of teachers
Tiring casework that is simplified by combinatorics class
Thanks so much for the detailed class participation summary! It is very helpful! [My daughter] said the class is very useful and more interactive activities than other virtual class she had before!
I fall asleep to prof. loh music every night and listen to his ted talk every night
We appreciate how much [our son] is learning and growing in this class. Thank you for making the world a better place through math and kindness!
I have high respect for Po-Shen, and was hoping for a while to get a first-hand view of this approach to online classes. [My daughter] didn't really let me observe too much, but she did confirm that this class was better than any other online classes she's had, and better than some in-person classes too. That's very impressive. Great job, everyone involved!
Thank you very much for explaining [my son's learning situation] in detail… I asked him about this course and he expressed that he was very interested and enjoyed learning this course. The school had a test for the most recent class, so I watched the replay in the afternoon. I think he gained something from this course. Thank you teacher!
[My daughter] enjoyed really much all the sessions she attended, thank you for the great teaching and animation!
u guys are my favorite pair of teachers
Tiring casework that is simplified by combinatorics class
Thanks so much for the detailed class participation summary! It is very helpful! [My daughter] said the class is very useful and more interactive activities than other virtual class she had before!
I fall asleep to prof. loh music every night and listen to his ted talk every night
We appreciate how much [our son] is learning and growing in this class. Thank you for making the world a better place through math and kindness!
I have high respect for Po-Shen, and was hoping for a while to get a first-hand view of this approach to online classes. [My daughter] didn't really let me observe too much, but she did confirm that this class was better than any other online classes she's had, and better than some in-person classes too. That's very impressive. Great job, everyone involved!
Thank you very much for explaining [my son's learning situation] in detail… I asked him about this course and he expressed that he was very interested and enjoyed learning this course. The school had a test for the most recent class, so I watched the replay in the afternoon. I think he gained something from this course. Thank you teacher!
[My daughter] enjoyed really much all the sessions she attended, thank you for the great teaching and animation!
u guys are my favorite pair of teachers
Tiring casework that is simplified by combinatorics class
Thanks so much for the detailed class participation summary! It is very helpful! [My daughter] said the class is very useful and more interactive activities than other virtual class she had before!
I fall asleep to prof. loh music every night and listen to his ted talk every night
We appreciate how much [our son] is learning and growing in this class. Thank you for making the world a better place through math and kindness!
I have high respect for Po-Shen, and was hoping for a while to get a first-hand view of this approach to online classes. [My daughter] didn't really let me observe too much, but she did confirm that this class was better than any other online classes she's had, and better than some in-person classes too. That's very impressive. Great job, everyone involved!
Thank you very much for explaining [my son's learning situation] in detail… I asked him about this course and he expressed that he was very interested and enjoyed learning this course. The school had a test for the most recent class, so I watched the replay in the afternoon. I think he gained something from this course. Thank you teacher!
[My daughter] enjoyed really much all the sessions she attended, thank you for the great teaching and animation!
u guys are my favorite pair of teachers
Tiring casework that is simplified by combinatorics class
Thanks so much for the detailed class participation summary! It is very helpful! [My daughter] said the class is very useful and more interactive activities than other virtual class she had before!
I fall asleep to prof. loh music every night and listen to his ted talk every night
We appreciate how much [our son] is learning and growing in this class. Thank you for making the world a better place through math and kindness!
I have high respect for Po-Shen, and was hoping for a while to get a first-hand view of this approach to online classes. [My daughter] didn't really let me observe too much, but she did confirm that this class was better than any other online classes she's had, and better than some in-person classes too. That's very impressive. Great job, everyone involved!
Thank you very much for explaining [my son's learning situation] in detail… I asked him about this course and he expressed that he was very interested and enjoyed learning this course. The school had a test for the most recent class, so I watched the replay in the afternoon. I think he gained something from this course. Thank you teacher!
[My daughter] enjoyed really much all the sessions she attended, thank you for the great teaching and animation!
u guys are my favorite pair of teachers
Tiring casework that is simplified by combinatorics class
Thanks so much for the detailed class participation summary! It is very helpful! [My daughter] said the class is very useful and more interactive activities than other virtual class she had before!
I fall asleep to prof. loh music every night and listen to his ted talk every night
We appreciate how much [our son] is learning and growing in this class. Thank you for making the world a better place through math and kindness!
I have high respect for Po-Shen, and was hoping for a while to get a first-hand view of this approach to online classes. [My daughter] didn't really let me observe too much, but she did confirm that this class was better than any other online classes she's had, and better than some in-person classes too. That's very impressive. Great job, everyone involved!
Thank you very much for explaining [my son's learning situation] in detail… I asked him about this course and he expressed that he was very interested and enjoyed learning this course. The school had a test for the most recent class, so I watched the replay in the afternoon. I think he gained something from this course. Thank you teacher!
[My daughter] enjoyed really much all the sessions she attended, thank you for the great teaching and animation!
u guys are my favorite pair of teachers
Tiring casework that is simplified by combinatorics class
Thanks so much for the detailed class participation summary! It is very helpful! [My daughter] said the class is very useful and more interactive activities than other virtual class she had before!
I fall asleep to prof. loh music every night and listen to his ted talk every night
We appreciate how much [our son] is learning and growing in this class. Thank you for making the world a better place through math and kindness!
I have high respect for Po-Shen, and was hoping for a while to get a first-hand view of this approach to online classes. [My daughter] didn't really let me observe too much, but she did confirm that this class was better than any other online classes she's had, and better than some in-person classes too. That's very impressive. Great job, everyone involved!
Thank you very much for explaining [my son's learning situation] in detail… I asked him about this course and he expressed that he was very interested and enjoyed learning this course. The school had a test for the most recent class, so I watched the replay in the afternoon. I think he gained something from this course. Thank you teacher!
[My daughter] enjoyed really much all the sessions she attended, thank you for the great teaching and animation!
u guys are my favorite pair of teachers
Tiring casework that is simplified by combinatorics class
Thanks so much for the detailed class participation summary! It is very helpful! [My daughter] said the class is very useful and more interactive activities than other virtual class she had before!
I fall asleep to prof. loh music every night and listen to his ted talk every night
We appreciate how much [our son] is learning and growing in this class. Thank you for making the world a better place through math and kindness!
I have high respect for Po-Shen, and was hoping for a while to get a first-hand view of this approach to online classes. [My daughter] didn't really let me observe too much, but she did confirm that this class was better than any other online classes she's had, and better than some in-person classes too. That's very impressive. Great job, everyone involved!
Thank you very much for explaining [my son's learning situation] in detail… I asked him about this course and he expressed that he was very interested and enjoyed learning this course. The school had a test for the most recent class, so I watched the replay in the afternoon. I think he gained something from this course. Thank you teacher!
[My daughter] enjoyed really much all the sessions she attended, thank you for the great teaching and animation!
u guys are my favorite pair of teachers
Tiring casework that is simplified by combinatorics class
Thanks so much for the detailed class participation summary! It is very helpful! [My daughter] said the class is very useful and more interactive activities than other virtual class she had before!
I fall asleep to prof. loh music every night and listen to his ted talk every night
We appreciate how much [our son] is learning and growing in this class. Thank you for making the world a better place through math and kindness!
I have high respect for Po-Shen, and was hoping for a while to get a first-hand view of this approach to online classes. [My daughter] didn't really let me observe too much, but she did confirm that this class was better than any other online classes she's had, and better than some in-person classes too. That's very impressive. Great job, everyone involved!
Thank you very much for explaining [my son's learning situation] in detail… I asked him about this course and he expressed that he was very interested and enjoyed learning this course. The school had a test for the most recent class, so I watched the replay in the afternoon. I think he gained something from this course. Thank you teacher!
[My daughter] enjoyed really much all the sessions she attended, thank you for the great teaching and animation!
u guys are my favorite pair of teachers
Tiring casework that is simplified by combinatorics class
Thanks so much for the detailed class participation summary! It is very helpful! [My daughter] said the class is very useful and more interactive activities than other virtual class she had before!
I fall asleep to prof. loh music every night and listen to his ted talk every night
We appreciate how much [our son] is learning and growing in this class. Thank you for making the world a better place through math and kindness!
I have high respect for Po-Shen, and was hoping for a while to get a first-hand view of this approach to online classes. [My daughter] didn't really let me observe too much, but she did confirm that this class was better than any other online classes she's had, and better than some in-person classes too. That's very impressive. Great job, everyone involved!
Thank you very much for explaining [my son's learning situation] in detail… I asked him about this course and he expressed that he was very interested and enjoyed learning this course. The school had a test for the most recent class, so I watched the replay in the afternoon. I think he gained something from this course. Thank you teacher!
[My daughter] enjoyed really much all the sessions she attended, thank you for the great teaching and animation!
u guys are my favorite pair of teachers
Tiring casework that is simplified by combinatorics class
Thanks so much for the detailed class participation summary! It is very helpful! [My daughter] said the class is very useful and more interactive activities than other virtual class she had before!
I fall asleep to prof. loh music every night and listen to his ted talk every night
We appreciate how much [our son] is learning and growing in this class. Thank you for making the world a better place through math and kindness!
I have high respect for Po-Shen, and was hoping for a while to get a first-hand view of this approach to online classes. [My daughter] didn't really let me observe too much, but she did confirm that this class was better than any other online classes she's had, and better than some in-person classes too. That's very impressive. Great job, everyone involved!
Thank you very much for explaining [my son's learning situation] in detail… I asked him about this course and he expressed that he was very interested and enjoyed learning this course. The school had a test for the most recent class, so I watched the replay in the afternoon. I think he gained something from this course. Thank you teacher!
[My daughter] enjoyed really much all the sessions she attended, thank you for the great teaching and animation!
u guys are my favorite pair of teachers
Tiring casework that is simplified by combinatorics class
Thanks so much for the detailed class participation summary! It is very helpful! [My daughter] said the class is very useful and more interactive activities than other virtual class she had before!
I fall asleep to prof. loh music every night and listen to his ted talk every night
We appreciate how much [our son] is learning and growing in this class. Thank you for making the world a better place through math and kindness!
I have high respect for Po-Shen, and was hoping for a while to get a first-hand view of this approach to online classes. [My daughter] didn't really let me observe too much, but she did confirm that this class was better than any other online classes she's had, and better than some in-person classes too. That's very impressive. Great job, everyone involved!
Thank you very much for explaining [my son's learning situation] in detail… I asked him about this course and he expressed that he was very interested and enjoyed learning this course. The school had a test for the most recent class, so I watched the replay in the afternoon. I think he gained something from this course. Thank you teacher!
[My daughter] enjoyed really much all the sessions she attended, thank you for the great teaching and animation!
u guys are my favorite pair of teachers
Tiring casework that is simplified by combinatorics class
Thanks so much for the detailed class participation summary! It is very helpful! [My daughter] said the class is very useful and more interactive activities than other virtual class she had before!
I fall asleep to prof. loh music every night and listen to his ted talk every night
We appreciate how much [our son] is learning and growing in this class. Thank you for making the world a better place through math and kindness!
I have high respect for Po-Shen, and was hoping for a while to get a first-hand view of this approach to online classes. [My daughter] didn't really let me observe too much, but she did confirm that this class was better than any other online classes she's had, and better than some in-person classes too. That's very impressive. Great job, everyone involved!
Thank you very much for explaining [my son's learning situation] in detail… I asked him about this course and he expressed that he was very interested and enjoyed learning this course. The school had a test for the most recent class, so I watched the replay in the afternoon. I think he gained something from this course. Thank you teacher!
[My daughter] enjoyed really much all the sessions she attended, thank you for the great teaching and animation!
u guys are my favorite pair of teachers
Tiring casework that is simplified by combinatorics class
Thanks so much for the detailed class participation summary! It is very helpful! [My daughter] said the class is very useful and more interactive activities than other virtual class she had before!
I fall asleep to prof. loh music every night and listen to his ted talk every night
We appreciate how much [our son] is learning and growing in this class. Thank you for making the world a better place through math and kindness!
I have high respect for Po-Shen, and was hoping for a while to get a first-hand view of this approach to online classes. [My daughter] didn't really let me observe too much, but she did confirm that this class was better than any other online classes she's had, and better than some in-person classes too. That's very impressive. Great job, everyone involved!
Thank you very much for explaining [my son's learning situation] in detail… I asked him about this course and he expressed that he was very interested and enjoyed learning this course. The school had a test for the most recent class, so I watched the replay in the afternoon. I think he gained something from this course. Thank you teacher!
[My daughter] enjoyed really much all the sessions she attended, thank you for the great teaching and animation!
u guys are my favorite pair of teachers
Tiring casework that is simplified by combinatorics class
Thanks so much for the detailed class participation summary! It is very helpful! [My daughter] said the class is very useful and more interactive activities than other virtual class she had before!
I fall asleep to prof. loh music every night and listen to his ted talk every night
We appreciate how much [our son] is learning and growing in this class. Thank you for making the world a better place through math and kindness!
I have high respect for Po-Shen, and was hoping for a while to get a first-hand view of this approach to online classes. [My daughter] didn't really let me observe too much, but she did confirm that this class was better than any other online classes she's had, and better than some in-person classes too. That's very impressive. Great job, everyone involved!
Thank you very much for explaining [my son's learning situation] in detail… I asked him about this course and he expressed that he was very interested and enjoyed learning this course. The school had a test for the most recent class, so I watched the replay in the afternoon. I think he gained something from this course. Thank you teacher!
[My daughter] enjoyed really much all the sessions she attended, thank you for the great teaching and animation!
u guys are my favorite pair of teachers
Tiring casework that is simplified by combinatorics class
Thanks so much for the detailed class participation summary! It is very helpful! [My daughter] said the class is very useful and more interactive activities than other virtual class she had before!
Syllabus
The 20 course meetings are split in 16 lessons (called Day 1 through Day 16 below), and 4 homework exam discussions. Each exam discussion meeting happens after 4 lessons.
Day 1
Permutations; counting with restrictions; counting with symmetry; tree diagram for representing outcomes; casework; counting pairs of objects; correction for overcounting
Day 2
Venn diagram; combinations; number of subsets; patterns in counting; sum of consecutive powers of 2; multiplication principle; complementary counting; counting lists of numbers with restrictions; overlapping groups
Day 3
Variation on Venn diagram; union and intersection of sets; set notation; inclusion-exclusion principle; prime factors; application of counting techniques to Number Theory; divisibility
Day 4
Counting on a grid; casework; patterns in counting; rotation and reflection; rotational symmetry and reflective symmetry; factorials; permutations and combinations; correcting for overcounting
Day 5
Permutations with repeated elements; multiplication principle; factorials; correction for overcounting; casework; binomial coefficients; "choose" notation; rotational and reflective symmetry
Day 6
Binomial coefficients; Pascal's triangle; symmetry of binomial coefficients; patterns in Pascal's triangle; Pascal's identity; comparing binomial coefficients; hockey stick identity; combinations; casework
Day 7
Binomial thm; Pascal's triangle, row sum of and relation to powers of 2; symmetry of binomial coefficients; number of subsets; powers of 11; applications of Binomial thm
Day 8
Casework; allocation-of-resource problems and arrangements; complementary counting; permutations with repeated elements; application of binomial coefficients
Day 9
Paths on a grid; using diagrams; permutations with repeated elements; factorials; binomial coefficients; complementary counting; reduction of a problem into subproblems; symmetry; difference of squares
Day 10
Tiling problems; recursive sequences; permutations with repeated elements; aₙ notation for elements of a sequence; binomial coefficients and choose notation; case analysis; Fibonacci sequences
Day 11
Correction for overcounting; patterns in counting; case analysis; counting with restrictions; multiple recursions; applications to recursion and tiling problems; general form of a recursive formula
Day 12
Graph theory basics; coloring problems; node, vertex, and graph; case analysis; symmetry; pigeonhole principle; four-color theorem; complementary counting; permutations; tree diagrams
Day 13
Counting ordered lists; case analysis; triangular numbers and their relationship to binomial coefficients; hockey stick identity; Pascal's triangle; ways to partition N objects (stars and bars); number of subsets
Day 14
Committee-type problems and ways to form pairs; correction for overcounting; permutations; factorials; multiplication principle; double factorial notation; applications of tiling techniques to word problems
Day 15
Application of counting techniques to word problems; shortest path problems; representing states using diagrams; breadth-first search technique
Day 16
Polyhedra vertices, edges and faces; Euler's polyhedral formula and motivation for; correction for overcounting; Platonic solids; stellated dodecahedron