**CTY’s mathematics, science, and computer science courses are dedicated to Dr. Richard P. Longaker, Provost of Johns Hopkins University from 1979 to 1987, in recognition of his advocacy and guidance through CTY’s initial years.**

In all of these courses, students have the opportunity to enrich or accelerate their studies. They investigate advanced concepts through a process of discovery and engagement that promotes a lifelong interest in these disciplines. Through hands-on, thought-provoking exercises, students learn to make connections between abstract ideas and their use in a range of fields, including science, engineering, and advanced mathematics.

Students who wish to receive credit or placement for CTY courses should consult with their home schools before registering to determine their schools’ policies and requirements, as these vary widely.

**Math, Computer Science, and Economic Courses**

Review eligibility for minimum test score requirements for math, computer science, and economics courses.

**Mathematics**

- Cryptology
- Combinatorics and Graph Theory
- Probability and Game Theory
- Mathematical Logic
- Number Theory
- Topology

**Computer Science**

**Economics**

Sample syllabi for all courses are also available with each course description. Please note that the sample syllabi are meant to provide an idea of the level of the course and whether or not the content area interests you. CTY instructors are given guidelines within which they each develop their own syllabi. Choice and sequencing of topics within the content area, as well as specific activities, labs, and assignments, will vary.

- Sample syllabus 1 (PDF)
- Sample syllabus 2 (PDF)

Cryptology is the study of the codes and ciphers used to create secret writing. In this math course, students begin their journey with an exploration of many early techniques for creating secret writing, such as cipher wheels, the Caesar shift, polyalphabetic substitution, and the Vigenère cipher. They move on to learn about modern techniques, including RSA public key cryptography, as students explore how data transmitted by computers can be secured with digital encryption. Discussions about the vulnerabilities of each encryption system enable students to attack and decrypt messages using techniques such as frequency analysis and cribbing. Students apply the concepts and learn to encrypt and decrypt their own secret messages.

Though the course’s central focus is on the mathematics of cryptology, the historical context of cryptography and cryptographic devices is provided to further develop an understanding of this branch of mathematics. For example, students examine the design and fallibility of the Enigma Machine, one of the most important cryptographic devices in history.

**Sample text:** *The Code Book*, Singh.

**Session 1:** *Canceled***Session 2:** *Canceled*

- Sample syllabus (PDF)

**Prerequisite:** Algebra I

This course begins with an exploration of enumerative combinatorics. Students use different techniques of mathematical proof and ideas in set theory to solve a variety of problems, and they study topics such as binomial coefficients, permutations, and partitions. For example, students employ bijective functions to turn seemingly tedious counting problems into much simpler problems, such as how to determine the number of games played in the March Madness tournament without needing to pull out your bracket and count one by one.

Students then investigate graph theory, an area of mathematics that is applied in fields such as computer science, counterterrorism, and navigation. One famous graph-theory question posed in the early 1800s—whether you can color any map using just four colors so that no two adjacent areas share the same color—took more than 100 years for mathematicians to answer in the affirmative. Students explore this question and other historic problems in graph theory as they delve into concepts such as cycles, planarity, algorithms, and graph colorings.

Along the way, students encounter problems that are challenging and fun, and that can be solved with creativity and determination—even without a background in college-level math.

**Note:** Students who have taken CTY's Discrete Math course **should not** take this course.

**Sample text:** Materials compiled by the instructor.

**Session 1:** *Canceled***Session 2:** *Canceled*

- Sample syllabus 1 (PDF)
- Sample syllabus 2 (PDF)

**Prerequisite:** Algebra I

The study of probability and game theory allows students to apply math to real-world situations. Game theory is a branch of mathematics focused on the application of mathematical reasoning to competitive behavior. In this course, students develop familiarity with some of the major tools of game theory, including dominance, mixed strategies, utility theory, Nash equilibria, and *n*-person games. In doing so, students also learn the necessary mathematical tools from probability and linear algebra to analyze and develop successful strategies in these games.

The games “played” by a budding game theorist in this course are abstract representations of real-life situations. For example, Nash equilibria have been used to solve questions of political competition and analyze penalty kicks in soccer, and the Prisoner’s Dilemma has been used to analyze the social networks of different populations. Class exercises involve individual and group work and may also include class tournaments.

**Sample texts:** *Game Theory and Strategy*, Straffin; *Thinking Strategically*, Dixit and Nalebuff.

**Session 1:** *Canceled***Session 2:** *Canceled*

- Sample syllabus 1 (PDF)
- Sample syllabus 2 (PDF)

**Prerequisite:** Algebra I

In this course, students learn about and practice what most mathematicians spend their time doing: proving or disproving conjectures. Students are introduced to the techniques of formal proofs and counterexamples. While the focus is on mathematical proofs, the logical reasoning skills developed serve as the building blocks of intellectual inquiry.

Students learn about the key concepts of logic, including validity, soundness, consistency, and satisfiability. They develop systems of logic in formal symbolic languages, including the propositional calculus and first-order quantified logic. These systems allow students to test the validity of arguments and write formal proofs with precision. Students explore the syntax (rules of grammar) and semantics (meanings of the symbols) of these languages. They then engage in metalogic: reasoning logically about a system of logic. They examine soundness, asking whether all proofs in the system really prove their conclusion, and completeness, considering whether every valid conclusion can actually be proved using the rules of that system.

By the end of the course, students become proficient at a skill essential to mathematicians: the ability to write proofs accurately and rigorously. Most importantly, students develop strong problem-solving skills and learn to think analytically—traits vital for rigorous inquiry in any field.

**Sample texts:** *Logic: Techniques of Formal Reasoning*, Kalish, Montague, and Mar; *Formal Logic: Its Scope and Limits*, Jeffrey.

**Session 1:** *Canceled***Session 2:** *Canceled*

- Sample syllabus 1 (PDF)
- Sample syllabus 2 (PDF)

**Prerequisites:** Geometry and Algebra II

Called “The Queen of Mathematics” by the great mathematician Carl Friedrich Gauss, number theory is the study of the natural numbers, the number system from which all others are derived. Despite the simplicity of the natural numbers, many accessible problems in number theory remain unsolved. For example, the Goldbach Conjecture, formulated in 1742, which posits that every even integer larger than 2 is the sum of two prime numbers, has defied all proof attempts.

In this proof-based course, students are introduced to the major ideas of elementary number theory and the historical framework in which these concepts were developed. While strengthening their ability to analyze and construct formal proofs, students explore topics such as the Euclidean Algorithm and continued fractions, Diophantine equations, Fibonacci numbers and the golden ratio, modular arithmetic, Fermat’s Little Theorem, RSA public key cryptography, and Fermat’s Two Square Theorem. Students leave the course with an appreciation for the elegance of theoretical mathematics and the ability to craft rigorous arguments.

**Sample text:** *Number Theory: A Lively Introduction with Proofs, Applications, and Stories*, Pommersheim, Marks, and Flapan.

**Session 1:** *Canceled***Session 2:** *Canceled*

- Sample syllabus (PDF)

**Prerequisites:** Geometry and Algebra II

Topology is the mathematical study of shapes and space that considers questions such as, “What objects that visually seem quite different share the same properties?” One of the major fields of mathematics, topology possesses wide-ranging applications and beautiful theorems with far-reaching consequences. This course introduces students to point-set topology as they delve into bizarre notions of “space” and develop skills with rigorous, proof-based mathematics.

Students begin by tackling the core concepts of sets, topologies, and continuous mappings before moving on to topological invariants such as compactness, connectedness, and the separation axioms. With these tools in hand, students understand why topology is the study of shape as they explore how to deform shapes and spaces without altering their fundamental properties. This knowledge allows students to see why it took 100 years for mathematicians to prove Poincaré’s 1904 conjecture about the nature of a sphere. The course concludes with a survey of applications of topology, such as how the study of knots influenced our understanding of proteins, or how the study of manifolds led to a deeper understanding of the topological shape of the universe.

**Sample text:** Materials compiled by the instructor.

**Session 1:** *Canceled***Session 2:** *Canceled*

- Sample syllabus 1 (PDF)
- Sample syllabus 2 (PDF)

**Prerequisite:** Algebra I

More than just a programming course, Fundamentals of Computer Science introduces students to three major areas of the discipline: theory and algorithms, hardware systems, and software systems. In the theoretical component of the course, students learn about algorithms, Boolean algebra, binary mathematics, and theory of computation. While studying hardware systems, they gain familiarity with the physical components of computers, digital logic, computer architecture, and computer networks. As students investigate software systems, they are introduced to elements of programming languages, compilers, computer graphics, and operating systems.

**Note:** Students may apply and illustrate some concepts they learn through work on programming projects. Learning a particular programming language is not a goal of the course.

**Sample text:** Materials compiled by the instructor.

**Lab Fee:** $135

**Session 1:** *Canceled***Session 2:** *Canceled*

- Sample syllabus 1 (PDF)
- Sample syllabus 2 (PDF)

**Prerequisite:** CTY’s Fundamentals of Computer Science, designated high-school-level CTY Online computer science classes, or at least a B+ in a high school or college-level computer programming course from an accredited provider.

In order for a computer to find a solution to a particular problem, it is necessary to formalize the problem in terms of a mathematical model, to find a suitable algorithm to solve the problem in that model, and to then implement the algorithm in a particular programming language. In this class, students learn how to design, analyze, and implement these algorithms.

Students begin by studying data structures such as arrays, lists, stacks, queues, trees, and sets in order to learn different ways of organizing data. Students then analyze many sorting, searching, and graphing algorithms to determine their runtime efficiency. By examining these fundamental algorithms, students learn how design decisions can affect the efficiency and scalability of an algorithm. A series of programming assignments helps students learn how to put these abstract ideas into practice. By the end of this course, students will acquire the conceptual tools necessary to model and analyze computational problems.

**Sample text:** *Data Structures and Algorithm Analysis*, Weiss.

**Session 1:** *Canceled***Session 2:** *Canceled*

- Sample syllabus 1 (PDF)
- Sample syllabus 2 (PDF)

**Prerequisite:** Algebra I. Students who are eligible for CTY Intensive Studies humanities courses may also take this course, so long as they have satisfied the Algebra I prerequisite.

Economist Alfred Marshall described economics as “the study of mankind in the ordinary business of life.” How much are you willing to pay for ice cream on a hot summer’s day? Who is responsible for the cost of pollution? Is there such a thing as a perfectly competitive market? Why has Google been accused of monopolistic practices? Microeconomics provides insights into these questions as it examines how individual buyers and sellers make decisions about allocating limited resources.

In this course, students analyze microeconomic theory and consider it in the context of today’s economic climate. They begin by studying the fundamental concepts of supply and demand curves, price elasticities, market structure, public goods, and externalities. Students build on this foundation to explore topics from the broad range of microeconomics: competition, consumer choice, monopoly, oligopoly, and the role of government in promoting greater efficiency and equity.

By applying mathematical concepts and critical analysis to economic theory, students uncover how economists analyze and predict changes in the behavior of both consumers and producers. Students leave the course with a firm foundation of central topics in microeconomics and a better understanding of practical economic issues that affect us all.

**Sample text:** *Principles of Microeconomics*, Mankiw.

**Session 1:** *Canceled***Session 2:** *Canceled*

- Sample syllabus 1 (PDF)
- Sample syllabus 2 (PDF)

**Prerequisite:** Algebra I. Students who are eligible for CTY Intensive Studies humanities courses may also take this course, so long as they have satisfied the Algebra I prerequisite.

What are the key indicators of an economy’s performance? How do governments craft monetary and fiscal policies to promote economic growth? What does it mean for a country to have a trade deficit? Analyzing economies at an aggregate level, macroeconomics—the study of economic systems—explores questions such as these, providing a bird’s-eye view of economic activity.

Students in this course explore fundamental concepts in macroeconomics, including national income, economic growth, inflation, employment, money, banking, financial markets, and the role of public policy. Building upon this foundation, students consider the global economy and issues in international trade and finance. Students examine comparative advantage and balance of payments, along with exchange rates and foreign currencies. By applying mathematical concepts to economic theory, students explore how economists analyze and predict changes in the economy.

Through lectures, readings, discussions, simulations, and research, students gain a firm grounding in macroeconomics and an introduction to central concepts in international trade and finance. Throughout the course, they draw from this knowledge to better understand the state of the U.S. and world economies today.

**Sample text:** *Macroeconomics*, Krugman and Wells.

**Session 1:** *Canceled***Session 2:** *Canceled*

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