Number Theory Worksheets

These worksheets are aimed at developing students’ comprehension and skills within the realm of number theory, a branch of mathematics concerned with the properties and relationships of integers. These worksheets typically feature a variety of exercises and problems focusing on concepts such as prime numbers, divisibility, factors and multiples, prime factorization, arithmetic sequences, and number patterns. Through engaging with these worksheets, students gain fluency in identifying and applying fundamental principles of number theory, which lays the foundation for more advanced mathematical concepts and problem-solving strategies.


Our Number Theory Curriculum Worksheet

Our Number Theory Curriculum Worksheets

Worksheet #1 | Answer Key

Worksheet #2 | Answer Key

Worksheet #3 | Answer Key

The Sieve of Eratosthenes Worksheet

The Sieve of Eratosthenes Worksheet

Sieve of Eratosthenes Answer Key


Number Theory is a branch of mathematics that focuses on the properties, relationships, and patterns of integers, or whole numbers. It is a fundamental area of study that explores the intrinsic characteristics of numbers, rather than their applications in other fields like physics or engineering. At its core, number theory investigates the behavior of numbers in various contexts, seeking to uncover underlying principles and structures.

One of the central topics in number theory is the study of prime numbers. Prime numbers are integers greater than 1 that have no divisors other than 1 and themselves. Understanding prime numbers is crucial in cryptography, where they form the basis for many encryption algorithms, ensuring secure communication over the internet. Prime numbers are also essential in fields such as computer science, where they are used in algorithms for tasks like generating random numbers and searching large datasets efficiently.

Divisibility is another key concept in number theory. It involves understanding the relationships between numbers and how they can be divided evenly without leaving a remainder. Divisibility rules, such as those for determining whether a number is divisible by 2, 3, 5, or other small primes, are not only useful in mathematical computations but also in everyday tasks such as checking whether a number is even or odd or finding common factors between numbers.

Factors and multiples, which are closely related to divisibility, play a significant role in number theory as well. Factors are numbers that divide a given integer without leaving a remainder, while multiples are the result of multiplying a number by an integer. Knowledge of factors and multiples is essential in various real-life scenarios, such as scheduling tasks, designing efficient transportation routes, or optimizing resource allocation in business operations.

Prime factorization is a fundamental technique in number theory that involves expressing a composite number as a product of its prime factors. This process is essential in simplifying fractions, finding the greatest common divisor (GCD) and least common multiple (LCM) of two or more numbers, and solving problems in algebra, geometry, and other branches of mathematics. Prime factorization also has practical applications in cryptography, where it forms the basis for algorithms used in security protocols like RSA encryption.

Arithmetic sequences and number patterns are also studied extensively in number theory. These sequences involve a series of numbers where each term is obtained by adding a fixed number, called the common difference, to the previous term. Understanding arithmetic sequences and patterns is valuable in fields such as finance, where they are used in calculating interest rates, loan payments, and investment returns. Additionally, number patterns can help identify trends in data analysis, inform decision-making processes, and predict future outcomes in various domains.