# Art and Craft of Mathematical Problem Solving

Course No. 1483
Professor Paul Zeitz, Ph.D.
University of San Francisco
4.3 out of 5
34 Reviews
79% of reviewers would recommend this product
Course No. 1483
Video Streaming Included Free

## Course Overview

One of life's most exhilarating experiences is the "aha!" moment that comes from pondering a mathematical problem and then seeing the way to an elegant solution. And many problems can be solved relatively quickly with the right strategy. For example, how fast can you find the sum of the numbers 1 + 2 + 3 up to 100? This was famously answered in the late 1700s by the 10-year-old Carl Friedrich Gauss, later to become one of history's greatest mathematicians. Young Gauss noticed that by starting at opposite ends of the string of numbers from 1 to 100, each successive pair adds up to 101:

1 + 100 = 101
2 + 99 = 101
3 + 98 = 101

and so on through the 50th pair,

50 + 51 = 101

Gauss was already thinking like a good problem solver: The sum of the numbers from 1 to 100 is 50 × 101, or 5,050—obtained in seconds and without a calculator!

In 24 mind-enriching lectures, The Art and Craft of Mathematical Problem Solving conducts you through scores of problems—at all levels of difficulty—under the inspiring guidance of award-winning Professor Paul Zeitz of the University of San Francisco, a former champion "mathlete" in national and international math competitions and a firm believer that mathematical problem solving is an important skill that can be nurtured in practically everyone.

These are not mathematical exercises, which Professor Zeitz defines as questions that you know how to answer by applying a specific procedure. Instead, problems are questions that you initially have no idea how to answer. A problem by its very nature requires exploration, resourcefulness, and adventure—and a rigorous proof is less important than no-holds-barred investigation.

Think More Lucidly, Logically, Creatively

Not only is solving such problems fun, but the techniques you learn come in handy whenever you are presented with an unfamiliar problem in mathematics, giving you the confidence to try different approaches until you make a breakthrough. Also, by learning a range of different problem-solving approaches in algebra, geometry, combinatorics, number theory, and other fields, you see how all of mathematics is tied together, and how techniques in one area can be used to solve problems in another.

Furthermore, entertaining math problems sharpen the mind, stimulating you to think more lucidly, logically, and creatively and allowing you to tackle intellectual challenges you might never have imagined.

And for those in high school or college, this course serves as an enriching mathematical experience, equal to anything available in the top schools. Professor Zeitz is a masterful coach of math teams at every level of competition, from beginners through international champions, and he knows how to inspire, encourage, and instruct.

Strategies, Tactics, and Tools of Math Masters

The Art and Craft of Mathematical Problem Solving is more than a bag of math tricks. Instead, Professor Zeitz has designed a series of lessons that take you through increasingly more challenging problems, illustrating a variety of strategies, tactics, and tools that you can use to overcome difficult math obstacles. His goal is to give you the persistence and creativity to turn over a problem in your mind for however long it takes to reach a solution.

The first step is to come up with a strategy—an overall plan of attack. Among the many strategies that Professor Zeitz discusses are these:

• Get your hands dirty: Dive in! Plug in numbers and see what happens. This is a superb starting strategy because it almost always shows a way to keep on investigating. You'll be surprised at how often a pattern emerges that takes you to the next step.
• Think outside the box: Break the bounds of conventional thinking. Professor Zeitz shows you the original think-outside-the-box problem, in which the key idea is to disregard the boundaries of an implied box. He also explains why he prefers to call this strategy "chainsaw the giraffe."
• Wishful thinking: Turn a hard problem into an easy one by removing the hard part. For example, substitute small numbers for big ones. This is a confidence-builder that often gives you a partial solution that shows you how to solve the original problem.
• Change your point of view: Every problem has a natural point of view, such as a time or place where something is happening. Step back and try a different point of view. This could mean recasting an algebra problem as one in geometry, or vice versa.

The next step after choosing a strategy is to find a suitable tactic. For example, suppose you live in a cabin that is two miles north of a river that runs east and west, and your grandma's cabin is 12 miles west and 1 mile north of your cabin. Every day you go to visit grandma, but first you stop by the river to get fresh water for her. What is the length of the route that has the minimum distance?

You start with the "draw a picture" strategy. Once you have something to look at, you realize that the "symmetry" tactic will give you the shortest distance. Here's how it works: Imagine an alternate you on the same errand but on the south side of the river, in a mirror image of the situation on the north side. By drawing a line connecting your real cabin with the alternate grandma's cabin, and another line connecting the real grandma's cabin and the one belonging to the alternate you, you find an intersecting point at the river that is the perfect place to stop.

On some problems you also need a special-purpose technique—a tool. For example, the 10-year-old Gauss's trick of pairing numbers in the earlier example is a tool whose underlying idea—symmetry—can be applied to a wide range of problems. You learn the strengths, as well as possible pitfalls, of such tools.

Prepare for an Exhilarating Experience

Professor Zeitz compares this systematic approach to problem solving—in which you deploy strategies, tactics, and tools—to the mountaineer's quest to reach the top of a high peak. The mountain may seem insurmountable, but there is always a way to conquer it by proceeding one step at a time.

Looking at an impressive mountain, you can't but feel a sense of awe at the prospect of climbing it. Math problems, too, can produce this same reaction. But don't be daunted: You are more ready than you think. So sharpen your pencil, get some paper, and prepare for the exhilarating experience of The Art and Craft of Mathematical Problem Solving.

24 lectures
|  Average 30 minutes each
• 1
Problems versus Exercises
Solving a math problem is like taking a hike, or even climbing a mountain. It's exciting, challenging, and unpredictable. Get started with three entertaining problems that plunge you into thinking like a problem solver and illustrate two useful strategies: "wishful thinking" and "get your hands dirty." x
• 2
Strategies and Tactics
Learn the difference between strategies, tactics, and tools when applied to problem solving. Try to decipher a puzzling reply to a census question, and determine whether three jumping frogs will ever land on a given point. x
• 3
The Problem Solver's Mind-Set
Delve deeper into the psychological aspects of problem solving—especially concentration, creativity, and confidence—and ways to enhance them. Learn to avoid overreliance on very narrowly focused mathematical tricks, and investigate a number of "think outside the box" problems, including the original that gave the name to this strategy. x
• 4
Searching for Patterns
Brainstorm an array of problems with the goal of building your receptiveness to discovery. See how far you can go by just letting yourself look for interesting patterns, experiencing both conjectures that work as well as cautionary examples of those that don't. The core of the lecture is an investigation into trapezoidal numbers and a search for patterns in Pascal's triangle. x
• 5
Closing the Deal—Proofs and Tools
Learn how to "close the deal" on some of the outstanding conjectures from the previous lecture by using airtight arguments, or proofs. These include deductive proof, proof by contradiction, and algorithmic proof—along with the narrow (and often overestimated) power of specific tools or "tricks," such as the "massage" tool, to make a mathematical expression simpler. x
• 6
Pictures, Recasting, and Points of View
Explore three strategies for achieving a problem-solving breakthrough: draw a picture, change your point of view, and recast the problem. Try these strategies on a selection of intriguing word problems that almost magically yield an answer, once you find a creative way of analyzing the situation. x
• 7
The Great Simplifier—Parity
Applying the problem-solving tactic of parity, test your wits against an evil wizard, an open-and-shut row of lockers, and other colorful conundrums. Then see how parity leads naturally into graph theory, a playground for investigation that has nothing to do with conventional graphs. x
• 8
The Great Unifier—Symmetry
Having used symmetrical principles to tackle problems in earlier lectures, take a closer look at this powerful tactic. Discover that when symmetry isn't evident, impose it! This approach lets you compute the shortest distance to grandma's when you first have to detour to a river to fetch water. x
• 9
Symmetry Wins Games!
Devise winning strategies for several fun but baffling combinatorial games. One is the "puppies and kittens" exercise, a series of moves and countermoves that can be taught to children but that is amazingly hard to play well; that is, until you uncover its secrets with symmetry and a few other ideas. x
• 10
Contemplate Extreme Values
Take your problem-solving skills to extremes on a variety of mathematical puzzles by learning how to contemplate the minimal or maximal values in a problem. This "extreme" principle is a simple idea, but it has the nearly magical ability to solve hard problems almost instantly. x
• 11
The Culture of Problem Solving
Detour into the hidden world of problem solvers—young people and their mentors who live and breathe nontraditional, nontextbook mathematics such as what you have been studying in this course. The movement is especially strong in Russia and eastern Europe but is catching on in the United States. x
• 12
Recasting Integers Geometrically
Delve deeply into the famous "chicken nuggets" problem. In brief, what's the largest number of nuggets that you can't order by combining boxes of 7 and 10 nuggets? There are many roads to a solution, but you focus on a visual approach by counting points in a geometric plane. x
• 13
Recasting Integers with Counting and Series
Apply the powerful strategies of recasting and rule-breaking to two classical theorems in number theory: Fermat's "little" theorem and Euler's proof of the infinitude of primes. x
• 14
Things in Categories—The Pigeonhole Tactic
According to the pigeonhole principle, if you try to put n + 1 pigeons into n pigeonholes, at least one hole will contain at least two pigeons. See how this simple idea can solve an amazing variety of problems. Also, delve into Ramsey theory, a systematic way of finding patterns in seemingly random structures. x
• 15
The Greatest Unifier of All—Invariants
To Professor Zeitz, the single most important word in all of mathematics is "invariants." Discover how this granddaddy of all problem-solving tactics—which involves quantities and qualities that stay unchanged—can be used almost anywhere and encompasses such ideas as symmetry and parity. x
• 16
Squarer Is Better—Optimizing 3s and 2s
What is the largest number that is the product of positive integers whose sum is 1,976? Tackle this question from the 1976 International Mathematical Olympiad with the method of algorithmic proof, in which you devise a sequence of steps—an algorithm—that is guaranteed to solve the problem. x
• 17
Using Physical Intuition—and Imagination
Draw on your skills developed so far to solve a tricky problem about marbles colliding on a circular track. Martin Gardner's airplane problem and a question about how many times a laser beam reflects between two intersecting mirrors help you warm up to a solution. x
• 18
Geometry and the Transformation Tactic
Focusing on geometry, consider some baffling problems that become almost trivial once you know how to apply rotations, reflections, and other geometric transformations of your normal point of view. This clever tactic was pioneered by the 19th-century mathematician Felix Klein. x
• 19
Building from Simple to Complex with Induction
Sometimes a problem demands a different type of proof from the ones you learned in Lecture 5. Study cases in which proof by mathematical induction is the only feasible approach. These typically occur in recursive situations, where a complicated structure emerges from a simpler one. x
• 20
Induction on a Grand Scale
Continuing your use of inductive proof, calculate the probability that a randomly chosen number in Pascal's triangle is even. This problem is surprisingly easy to investigate, but it requires sophistication to resolve. But by now you have a good grasp of the methods you need. x
• 21
Recasting Numbers as Polynomials—Weird Dice
Is it possible to find weird dice that "play fairly"? These are two dice that are numbered differently from standard dice but that have the same probability of rolling 2, 3, 4, and so on through 12. Learn that, amazingly, the answer is yes. x
• 22
A Relentless Tactic Solves a Very Hard Problem
In a lecture that Professor Zeitz compares to walking along a mathematical cliff edge, use the pigeonhole principle to find patterns within apparently random and mind-bogglingly large structures. You'll discover there is no limit to what the intrepid problem solver can do. x
• 23
Genius and Conway's Infinite Checkers Problem
No course on problem solving is complete without a look at the checkers problem, formulated by contemporary mathematician and puzzle-master John Conway. Also learn about two other icons in the field: Paul Erdos, who died in 1996, and Évariste Galois, who lived in the early 1800s. x
• 24
How versus Why—The Final Frontier
Professor Zeitz reviews problem-solving tactics and introduces one final topic, complex numbers, before recommending a mission to last a lifetime: the quest for why a solution to any given problem is true, not just how it was obtained. He closes by sharing some of his favorite examples of this elusive intellectual quest. x

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## What's Included

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##### Instant Video Includes:
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• 24 lectures on 4 DVDs
• 152-page printed course guidebook
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##### Course Guidebook Details:
• 152-page printed course guidebook
• Equations, tables, & diagrams
• Solutions

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Paul Zeitz, Ph.D.
University of San Francisco
Dr. Paul Zeitz is Professor of Mathematics at the University of San Francisco. He majored in history at Harvard and received a Ph.D. in Mathematics from the University of California, Berkeley, in 1992, specializing in ergodic theory. One of his greatest interests is mathematical problem solving. He won the USA Mathematical Olympiad (USAMO) and was a member of the first American team to participate in the International...
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## Reviews

Art and Craft of Mathematical Problem Solving is rated 4.3 out of 5 by 33.
Rated 1 out of 5 by from I started this course and took the first two lectures. In the first lecture the professor presented a pill problem and its supposed solution. The solution was wrong and did not solve the problem since one could randomly take the wrong dose of pills and that was not accounted for. I could not stop thinking about this error for the rest of the lectures so I just had to stop the lectures.
Date published: 2020-07-15
Rated 5 out of 5 by from I'm so happy to learn different ways to solve problems.
Date published: 2020-06-01
Rated 5 out of 5 by from I wish more mathematics courses were like this on. Art and Craft of Mathematical Problem Solving was the first Learning Company course I ever bought and, although I have bought other courses since, this one remains my clear favourite. Even though I have some prior background in mathematics and problem solving, this course was still challenging - and that is why it is so great. Too many courses avoid presenting the learner with real challenges and instead provide intellectual entertainment. In my opinion, in the "hard"sciences at least, if you are not presented with problems that require deep thinking and problem-solving struggle then you are not really learning. So if you want a real learning opportunity try this course. If you merely want entertainment try something else.
Date published: 2020-04-12
Rated 5 out of 5 by from things to which you never were introduced in math having fun watching slowly, either forgot or never had decent profs. The guy who taught Pre Calc was head of dept. He was so well versed but then it was a passion and he had all sorts of interesting things to teach about all maths the others in dept. did not. This DVD will fill in the blanks!!!
Date published: 2019-07-03
Rated 5 out of 5 by from Professional production Very professional and thought provoking, another excellent tool for the Mathematically inclined life long learner.
Date published: 2019-02-04
Rated 5 out of 5 by from A Delightful Challenge! This course offers delightful techniques and methods for solving difficult math problems. But be warned: it is NOT a sit-back-and-watch course. It will take effort to follow. But it's well worth the effort!
Date published: 2018-06-03
Rated 5 out of 5 by from Mathletes will love this; others - YMMV Read carefully through the course description; it's quite accurate. If you find it provocative and exciting, get the course! It is an excellent and detailed discussion of approaches to solving the sort of math problems tackled by high school math teams, and many fascinating (and some not-so-fascinating) problems are described and solved in detail. It is for mathletes that I rate the course a '5'. As others have made clear, however, there is very little (if anything) here that can be applied to other areas of life. Even within mathematics this is a narrow area of interest. If you don't already know you love math, look elsewhere! Professor Zeitz is certainly expert and enthusiastic. His explanations are generally clear, if you take the time to understand them, although he is not always the smoothest speaker. And I personally did not appreciate the pep talk scattered throughout the course, such as "a good problem solver is intellectually playful and fearless" and "problem solving . . . is a lifestyle with a culture. The true underpinnings of this culture are passion and persistence." I imagine this might be helpful for high schoolers, as our professor has been extremely successful in guiding them. Full disclosure: I was an alternate (a few years ago . . .) on my high school math team at the Bronx High School of Science, so I do have an interest in this area, albeit not a very high aptitude. A little of the history of mathematics related to this subject is presented, as well as very brief biographical sketches of some of the greats. I would actually have liked more of this, but it is certainly outside the focus of the course. The Course Guidebook includes detailed treatments of the problems discussed, and will be very helpful if you don't catch on the first time around. So - an excellent course for those with a particular interest in this area. Choose carefully, and if you take it, enjoy.
Date published: 2018-05-16
Rated 1 out of 5 by from Puzzle Solving, not Problem Solving "How you communicate knowledge is just as important as the knowledge itself." I still remember an introductory chemistry professor making this statement on the first day of class in late August 1983. I have no doubt that Prof. Zeitz is mathematically brilliant, and perhaps in person he is very relaxed. In technical skills, he is undoubtedly very well prepared to coach the math Olympiad team and to teach mathematical puzzle seminars. However, his on-camera presentation skills and demeanor - his methods of communicating knowledge to his video class - need an overhaul. As my 10 year old daughter said one night after as I was watching, "He looks very nervous." I will go a step further and say extremely uncomfortable. The professor rarely let go of the lectern, and for all but a few minutes of the first 11 hours, stood as stiff as brick wall. Every professor (and non-professor) has his/her idiosyncrasies, but after the 22nd lecture (of 24), I stopped watching. Of the 10 to 15 Great Courses that I have watched, Prof. Zeitz is the first one whom I thought was a poor communicator in the video classroom. The course content focuses on solving mathematical puzzles. Example: you can buy chicken nuggets in packets of five or seven; what is the largest number of nuggets that, in any combination of five and seven-piece packets, that you cannot buy? If there is a connection from the tactics and strategies of math Olympiad-style puzzles to the harder problems of single variable calculus and differential equations, I never saw it. Perhaps the professor would need another 24 lectures to draw those connections. If you are interested in mathematical puzzles, you will probably find this course interesting and fascinating. If you want to learn the more practical skills to solve the harder problems (what Prof. Zeitz would call exercises) of calculus, differential equations and other college sophomore level courses, this is not the course for you.
Date published: 2018-02-24