Number Theory. Applications of Congruences. Francis Joseph Campena Mathematics Department De La Salle University-Manila

Size: px
Start display at page:

Download "Number Theory. Applications of Congruences. Francis Joseph Campena Mathematics Department De La Salle University-Manila"

Transcription

1 Number Theory Applications of Congruences Francis Joseph Campena Mathematics Department De La Salle University-Manila

2 Introduction Divisibility Test In this section, we discuss some divisibility rules for 10, 5, 2 i, 3,9, and 11. First, let us consider the decimal representation of a number N = n k 10 k + n k 1 10 k n n n 0.

3 Theorem (Divisibility for 10) An integer n is divisible by 10 if and only if n n 0 is the units digit of n is 0. mod 10, that Theorem (Divisibility for 5) An integer n is divisible by 5 if and only if 5 n 0, that is the units digit of n is either 0 or 5. Theorem (Divisibility for 2 i ) An integer n is divisible by 2 i if and only if the number formed by the last i digits in n is divisible by 2 i.

4 Theorem (Divisibility for 3) An integer n is divisible by 3 if and only if the k i=0 n i is divisible by 3; that is the sum of the digits of the number is divisible by 3. Theorem (Divisibility for 9) An integer n is divisible by 9 if and only if the k i=0 n i is divisible by 9; that is the sum of the digits of the number is divisible by 9. Theorem (Divisibility for 11) An integer n is divisible by 11 if and only if the even n i odd n i is divisible by 11; that is the sum of the digits of the number is divisible by 11.

5 Introduction Divisibility Test Modular arithmetic can be used to create beautiful designs. We will now explore three such designs: an m-pointed star, an (m, n) residue design, and quilt designs. They are really fun, so enjoy them.

6 m-pointed star Divisibility Test To construct an m-pointed star, mark m equally spaced points on a large circle, and label them with the least residues 0 through (m 1) modulo m. Choose a least residue i modulo m, where (i, m) = 1. Join each point x with the point x + i modulo m. Now color in the various regions inside the circle with some solid colors. You should get a nice m-pointed star.

7 (m, n)residuedesign To construct an (m, n) residue design, where 1 n m and (m, n) = 1, select m 1 equally spaced points on a large circle, label them 1 through m 1, and join each point x to point nx modulo m. Then color in the various regions formed in a systematic way to create exciting designs.

8 (m, n)residuedesign

9 (m, n)residuedesign

10 (m, n)residuedesign

11 Quilt Designs Divisibility Test We can use addition and multiplication tables for least residues modulo m to generate other artistic and interesting designs. For example, choose m = 9. Construct the addition table for the set of least residues 0 through 8 modulo 9, as shown below.

12 Quilt Designs Divisibility Test Devise nine basic design elements to represent each of the numbers 0 through 8. For instance,

13 Quilt Designs Divisibility Test Replacing each entry in the multiplication table for the least residue modulo 9 with the devised basic design, we have

14 Quilt Designs Divisibility Test For example, flip this design about its right-side edge and then flip the ensuing design about the bottom edge.

15 Details Divisibility Test 1. Form a group of 3 members. 2. Select one project from the given list. 3. Construct a module that allows you to discuss the project to a senior highschool class. 4. Provide the necessary resource guides/instructors manual, references and examples so that any teacher with sufficient background could implement the lesson.

16 Project 1: Check Digits Discuss how the theory of congruences is applied to coding theory. Specifically on the UPC (universal product codes) found on grocery items and ISBN (International Standard Book Number). You may also include other applications such as the Vehicle Identification Number of automobiles or International Article Numberting Assocication (European Article Numbering Association). Provide some examples in each application.

17 Project 2: Round Robin Tournaments Discuss how the theory of congruences is used in constructing a schedule in which each contestant meets each other contestant in turn. Provide a simple algorithm that discuss a way to construct a round robin schedule for n teams/players. Provide some examples for some small number of players/teams.

18 Project 3: Perpetual Calendar First provide a historical background on the development of the calendar that is now widely used today. Develop an alorithm to determine the day of the week for any date in any year. Provide some illustrations.

19 Project 4: Applications to Cryptography Provide a simple background on what cryptography is all about and how is the theory of congruences applied to some topics in cryptography/cryptosystems. Provide some simple illustrations.

Modular Arithmetic. claserken. July 2016

Modular Arithmetic. claserken. July 2016 Modular Arithmetic claserken July 2016 Contents 1 Introduction 2 2 Modular Arithmetic 2 2.1 Modular Arithmetic Terminology.................. 2 2.2 Properties of Modular Arithmetic.................. 2 2.3

More information

Modular arithmetic Math 2320

Modular arithmetic Math 2320 Modular arithmetic Math 220 Fix an integer m 2, called the modulus. For any other integer a, we can use the division algorithm to write a = qm + r. The reduction of a modulo m is the remainder r resulting

More information

MODULAR ARITHMETIC II: CONGRUENCES AND DIVISION

MODULAR ARITHMETIC II: CONGRUENCES AND DIVISION MODULAR ARITHMETIC II: CONGRUENCES AND DIVISION MATH CIRCLE (BEGINNERS) 02/05/2012 Modular arithmetic. Two whole numbers a and b are said to be congruent modulo n, often written a b (mod n), if they give

More information

An interesting class of problems of a computational nature ask for the standard residue of a power of a number, e.g.,

An interesting class of problems of a computational nature ask for the standard residue of a power of a number, e.g., Binary exponentiation An interesting class of problems of a computational nature ask for the standard residue of a power of a number, e.g., What are the last two digits of the number 2 284? In the absence

More information

Foundations of Cryptography

Foundations of Cryptography Foundations of Cryptography Ville Junnila viljun@utu.fi Department of Mathematics and Statistics University of Turku 2015 Ville Junnila viljun@utu.fi Lecture 10 1 of 17 The order of a number (mod n) Definition

More information

Cryptography Lecture 1: Remainders and Modular Arithmetic Spring 2014 Morgan Schreffler Office: POT 902

Cryptography Lecture 1: Remainders and Modular Arithmetic Spring 2014 Morgan Schreffler Office: POT 902 Cryptography Lecture 1: Remainders and Modular Arithmetic Spring 2014 Morgan Schreffler Office: POT 902 http://www.ms.uky.edu/~mschreffler Topic Idea: Cryptography Our next topic is something called Cryptography,

More information

Modular Arithmetic and Doomsday

Modular Arithmetic and Doomsday Modular Arithmetic and Doomsday Blake Thornton Much of this is due directly to Joshua Zucker and Paul Zeitz. 1. Subtraction Magic Trick. While blindfolded, a magician asks a member from the audience to

More information

1 = 3 2 = 3 ( ) = = = 33( ) 98 = = =

1 = 3 2 = 3 ( ) = = = 33( ) 98 = = = Math 115 Discrete Math Final Exam December 13, 2000 Your name It is important that you show your work. 1. Use the Euclidean algorithm to solve the decanting problem for decanters of sizes 199 and 98. In

More information

6.2 Modular Arithmetic

6.2 Modular Arithmetic 6.2 Modular Arithmetic Every reader is familiar with arithmetic from the time they are three or four years old. It is the study of numbers and various ways in which we can combine them, such as through

More information

Math Runes. Abstract. Introduction. Figure 1: Viking runes

Math Runes. Abstract. Introduction. Figure 1: Viking runes Proceedings of Bridges 2013: Mathematics, Music, Art, Architecture, Culture Math Runes Mike Naylor Norwegian center for mathematics education (NSMO) Norwegian Technology and Science University (NTNU) 7491

More information

Grade 6/7/8 Math Circles April 1/2, Modular Arithmetic

Grade 6/7/8 Math Circles April 1/2, Modular Arithmetic Faculty of Mathematics Waterloo, Ontario N2L 3G1 Modular Arithmetic Centre for Education in Mathematics and Computing Grade 6/7/8 Math Circles April 1/2, 2014 Modular Arithmetic Modular arithmetic deals

More information

Discrete Square Root. Çetin Kaya Koç Winter / 11

Discrete Square Root. Çetin Kaya Koç  Winter / 11 Discrete Square Root Çetin Kaya Koç koc@cs.ucsb.edu Çetin Kaya Koç http://koclab.cs.ucsb.edu Winter 2017 1 / 11 Discrete Square Root Problem The discrete square root problem is defined as the computation

More information

Number Theory - Divisibility Number Theory - Congruences. Number Theory. June 23, Number Theory

Number Theory - Divisibility Number Theory - Congruences. Number Theory. June 23, Number Theory - Divisibility - Congruences June 23, 2014 Primes - Divisibility - Congruences Definition A positive integer p is prime if p 2 and its only positive factors are itself and 1. Otherwise, if p 2, then p

More information

1 Introduction. 2 An Easy Start. KenKen. Charlotte Teachers Institute, 2015

1 Introduction. 2 An Easy Start. KenKen. Charlotte Teachers Institute, 2015 1 Introduction R is a puzzle whose solution requires a combination of logic and simple arithmetic and combinatorial skills 1 The puzzles range in difficulty from very simple to incredibly difficult Students

More information

Fermat s little theorem. RSA.

Fermat s little theorem. RSA. .. Computing large numbers modulo n (a) In modulo arithmetic, you can always reduce a large number to its remainder a a rem n (mod n). (b) Addition, subtraction, and multiplication preserve congruence:

More information

b) Find all positive integers smaller than 200 which leave remainder 1, 3, 4 upon division by 3, 5, 7 respectively.

b) Find all positive integers smaller than 200 which leave remainder 1, 3, 4 upon division by 3, 5, 7 respectively. Solutions to Exam 1 Problem 1. a) State Fermat s Little Theorem and Euler s Theorem. b) Let m, n be relatively prime positive integers. Prove that m φ(n) + n φ(m) 1 (mod mn). Solution: a) Fermat s Little

More information

Solutions to Problem Set 6 - Fall 2008 Due Tuesday, Oct. 21 at 1:00

Solutions to Problem Set 6 - Fall 2008 Due Tuesday, Oct. 21 at 1:00 18.781 Solutions to Problem Set 6 - Fall 008 Due Tuesday, Oct. 1 at 1:00 1. (Niven.8.7) If p 3 is prime, how many solutions are there to x p 1 1 (mod p)? How many solutions are there to x p 1 (mod p)?

More information

Two congruences involving 4-cores

Two congruences involving 4-cores Two congruences involving 4-cores ABSTRACT. The goal of this paper is to prove two new congruences involving 4- cores using elementary techniques; namely, if a 4 (n) denotes the number of 4-cores of n,

More information

Linear Congruences. The solutions to a linear congruence ax b (mod m) are all integers x that satisfy the congruence.

Linear Congruences. The solutions to a linear congruence ax b (mod m) are all integers x that satisfy the congruence. Section 4.4 Linear Congruences Definition: A congruence of the form ax b (mod m), where m is a positive integer, a and b are integers, and x is a variable, is called a linear congruence. The solutions

More information

1.6 Congruence Modulo m

1.6 Congruence Modulo m 1.6 Congruence Modulo m 47 5. Let a, b 2 N and p be a prime. Prove for all natural numbers n 1, if p n (ab) and p - a, then p n b. 6. In the proof of Theorem 1.5.6 it was stated that if n is a prime number

More information

Mathematics Explorers Club Fall 2012 Number Theory and Cryptography

Mathematics Explorers Club Fall 2012 Number Theory and Cryptography Mathematics Explorers Club Fall 2012 Number Theory and Cryptography Chapter 0: Introduction Number Theory enjoys a very long history in short, number theory is a study of integers. Mathematicians over

More information

Senior Math Circles February 10, 2010 Game Theory II

Senior Math Circles February 10, 2010 Game Theory II 1 University of Waterloo Faculty of Mathematics Centre for Education in Mathematics and Computing Senior Math Circles February 10, 2010 Game Theory II Take-Away Games Last Wednesday, you looked at take-away

More information

A Quick Introduction to Modular Arithmetic

A Quick Introduction to Modular Arithmetic A Quick Introduction to Modular Arithmetic Art Duval University of Texas at El Paso November 16, 2004 1 Idea Here are a few quick motivations for modular arithmetic: 1.1 Sorting integers Recall how you

More information

Math 1111 Math Exam Study Guide

Math 1111 Math Exam Study Guide Math 1111 Math Exam Study Guide The math exam will cover the mathematical concepts and techniques we ve explored this semester. The exam will not involve any codebreaking, although some questions on the

More information

Groups, Modular Arithmetic and Geometry

Groups, Modular Arithmetic and Geometry Groups, Modular Arithmetic and Geometry Pupil Booklet 2012 The Maths Zone www.themathszone.co.uk Modular Arithmetic Modular arithmetic was developed by Euler and then Gauss in the late 18th century and

More information

6. Find an inverse of a modulo m for each of these pairs of relatively prime integers using the method

6. Find an inverse of a modulo m for each of these pairs of relatively prime integers using the method Exercises Exercises 1. Show that 15 is an inverse of 7 modulo 26. 2. Show that 937 is an inverse of 13 modulo 2436. 3. By inspection (as discussed prior to Example 1), find an inverse of 4 modulo 9. 4.

More information

Math 412: Number Theory Lecture 6: congruence system and

Math 412: Number Theory Lecture 6: congruence system and Math 412: Number Theory Lecture 6: congruence system and classes Gexin Yu gyu@wm.edu College of William and Mary Chinese Remainder Theorem Chinese Remainder Theorem: let m 1, m 2,..., m k be pairwise coprimes.

More information

Fall. Spring. Possible Summer Topics

Fall. Spring. Possible Summer Topics Fall Paper folding: equilateral triangle (parallel postulate and proofs of theorems that result, similar triangles), Trisect a square paper Divisibility by 2-11 and by combinations of relatively prime

More information

Number Theory/Cryptography (part 1 of CSC 282)

Number Theory/Cryptography (part 1 of CSC 282) Number Theory/Cryptography (part 1 of CSC 282) http://www.cs.rochester.edu/~stefanko/teaching/11cs282 1 Schedule The homework is due Sep 8 Graded homework will be available at noon Sep 9, noon. EXAM #1

More information

The congruence relation has many similarities to equality. The following theorem says that congruence, like equality, is an equivalence relation.

The congruence relation has many similarities to equality. The following theorem says that congruence, like equality, is an equivalence relation. Congruences A congruence is a statement about divisibility. It is a notation that simplifies reasoning about divisibility. It suggests proofs by its analogy to equations. Congruences are familiar to us

More information

Appointment Sheet. 1 st Appointment. 2 nd Appointment. 3 rd Appointment. 4 th Appointment. 5 th Appointment. 6 th Appointment

Appointment Sheet. 1 st Appointment. 2 nd Appointment. 3 rd Appointment. 4 th Appointment. 5 th Appointment. 6 th Appointment Transparency / Handout 6A-1 Appointment Sheet 1 st Appointment 2 nd Appointment 3 rd Appointment 4 th Appointment 5 th Appointment 6 th Appointment Day 6: Section A Clock Arithmetic Page 9 Transparency

More information

Discrete Math Class 4 ( )

Discrete Math Class 4 ( ) Discrete Math 37110 - Class 4 (2016-10-06) 41 Division vs congruences Instructor: László Babai Notes taken by Jacob Burroughs Revised by instructor DO 41 If m ab and gcd(a, m) = 1, then m b DO 42 If gcd(a,

More information

Example Enemy agents are trying to invent a new type of cipher. They decide on the following encryption scheme: Plaintext converts to Ciphertext

Example Enemy agents are trying to invent a new type of cipher. They decide on the following encryption scheme: Plaintext converts to Ciphertext Cryptography Codes Lecture 3: The Times Cipher, Factors, Zero Divisors, and Multiplicative Inverses Spring 2015 Morgan Schreffler Office: POT 902 http://www.ms.uky.edu/~mschreffler New Cipher Times Enemy

More information

MATH 324 Elementary Number Theory Solutions to Practice Problems for Final Examination Monday August 8, 2005

MATH 324 Elementary Number Theory Solutions to Practice Problems for Final Examination Monday August 8, 2005 MATH 324 Elementary Number Theory Solutions to Practice Problems for Final Examination Monday August 8, 2005 Deartment of Mathematical and Statistical Sciences University of Alberta Question 1. Find integers

More information

Calculators will not be permitted on the exam. The numbers on the exam will be suitable for calculating by hand.

Calculators will not be permitted on the exam. The numbers on the exam will be suitable for calculating by hand. Midterm #2: practice MATH 311 Intro to Number Theory midterm: Thursday, Oct 20 Please print your name: Calculators will not be permitted on the exam. The numbers on the exam will be suitable for calculating

More information

Application: Public Key Cryptography. Public Key Cryptography

Application: Public Key Cryptography. Public Key Cryptography Application: Public Key Cryptography Suppose I wanted people to send me secret messages by snail mail Method 0. I send a padlock, that only I have the key to, to everyone who might want to send me a message.

More information

UNIVERSITY OF MANITOBA DATE: December 7, FINAL EXAMINATION TITLE PAGE TIME: 3 hours EXAMINER: M. Davidson

UNIVERSITY OF MANITOBA DATE: December 7, FINAL EXAMINATION TITLE PAGE TIME: 3 hours EXAMINER: M. Davidson TITLE PAGE FAMILY NAME: (Print in ink) GIVEN NAME(S): (Print in ink) STUDENT NUMBER: SEAT NUMBER: SIGNATURE: (in ink) (I understand that cheating is a serious offense) INSTRUCTIONS TO STUDENTS: This is

More information

Arithmetic Sequences Read 8.2 Examples 1-4

Arithmetic Sequences Read 8.2 Examples 1-4 CC Algebra II HW #8 Name Period Row Date Arithmetic Sequences Read 8.2 Examples -4 Section 8.2 In Exercises 3 0, tell whether the sequence is arithmetic. Explain your reasoning. (See Example.) 4. 2, 6,

More information

Number Theory. Konkreetne Matemaatika

Number Theory. Konkreetne Matemaatika ITT9131 Number Theory Konkreetne Matemaatika Chapter Four Divisibility Primes Prime examples Factorial Factors Relative primality `MOD': the Congruence Relation Independent Residues Additional Applications

More information

Distribution of Primes

Distribution of Primes Distribution of Primes Definition. For positive real numbers x, let π(x) be the number of prime numbers less than or equal to x. For example, π(1) = 0, π(10) = 4 and π(100) = 25. To use some ciphers, we

More information

Data security (Cryptography) exercise book

Data security (Cryptography) exercise book University of Debrecen Faculty of Informatics Data security (Cryptography) exercise book 1 Contents 1 RSA 4 1.1 RSA in general.................................. 4 1.2 RSA background.................................

More information

LECTURE 7: POLYNOMIAL CONGRUENCES TO PRIME POWER MODULI

LECTURE 7: POLYNOMIAL CONGRUENCES TO PRIME POWER MODULI LECTURE 7: POLYNOMIAL CONGRUENCES TO PRIME POWER MODULI 1. Hensel Lemma for nonsingular solutions Although there is no analogue of Lagrange s Theorem for prime power moduli, there is an algorithm for determining

More information

Fun Challenges Problem Solving Reasoning Deductive Thinking Convergent/Divergent Thinking Mind-Bending Challenges Critical Thinking

Fun Challenges Problem Solving Reasoning Deductive Thinking Convergent/Divergent Thinking Mind-Bending Challenges Critical Thinking Fun Challenges Problem Solving Reasoning Deductive Thinking Convergent/Divergent Thinking Mind-ending Challenges Critical Thinking Magic Shapes #1 Magic Shapes #1 Directions: Write the numbers 1 through

More information

Sheet 1: Introduction to prime numbers.

Sheet 1: Introduction to prime numbers. Option A Hand in at least one question from at least three sheets Sheet 1: Introduction to prime numbers. [provisional date for handing in: class 2.] 1. Use Sieve of Eratosthenes to find all prime numbers

More information

MAT Modular arithmetic and number theory. Modular arithmetic

MAT Modular arithmetic and number theory. Modular arithmetic Modular arithmetic 1 Modular arithmetic may seem like a new and strange concept at first The aim of these notes is to describe it in several different ways, in the hope that you will find at least one

More information

Cryptography Math 1580 Silverman First Hour Exam Mon Oct 2, 2017

Cryptography Math 1580 Silverman First Hour Exam Mon Oct 2, 2017 Name: Cryptography Math 1580 Silverman First Hour Exam Mon Oct 2, 2017 INSTRUCTIONS Read Carefully Time: 50 minutes There are 5 problems. Write your name legibly at the top of this page. No calculators

More information

Overview. The Big Picture... CSC 580 Cryptography and Computer Security. January 25, Math Basics for Cryptography

Overview. The Big Picture... CSC 580 Cryptography and Computer Security. January 25, Math Basics for Cryptography CSC 580 Cryptography and Computer Security Math Basics for Cryptography January 25, 2018 Overview Today: Math basics (Sections 2.1-2.3) To do before Tuesday: Complete HW1 problems Read Sections 3.1, 3.2

More information

Dice Activities for Algebraic Thinking

Dice Activities for Algebraic Thinking Foreword Dice Activities for Algebraic Thinking Successful math students use the concepts of algebra patterns, relationships, functions, and symbolic representations in constructing solutions to mathematical

More information

Example Enemy agents are trying to invent a new type of cipher. They decide on the following encryption scheme: Plaintext converts to Ciphertext

Example Enemy agents are trying to invent a new type of cipher. They decide on the following encryption scheme: Plaintext converts to Ciphertext Cryptography Codes Lecture 4: The Times Cipher, Factors, Zero Divisors, and Multiplicative Inverses Spring 2014 Morgan Schreffler Office: POT 902 http://www.ms.uky.edu/~mschreffler New Cipher Times Enemy

More information

MTH 3527 Number Theory Quiz 10 (Some problems that might be on the quiz and some solutions.) 1. Euler φ-function. Desribe all integers n such that:

MTH 3527 Number Theory Quiz 10 (Some problems that might be on the quiz and some solutions.) 1. Euler φ-function. Desribe all integers n such that: MTH 7 Number Theory Quiz 10 (Some roblems that might be on the quiz and some solutions.) 1. Euler φ-function. Desribe all integers n such that: (a) φ(n) = Solution: n = 4,, 6 since φ( ) = ( 1) =, φ() =

More information

MATH 135 Algebra, Solutions to Assignment 7

MATH 135 Algebra, Solutions to Assignment 7 MATH 135 Algebra, Solutions to Assignment 7 1: (a Find the smallest non-negative integer x such that x 41 (mod 9. Solution: The smallest such x is the remainder when 41 is divided by 9. We have 41 = 9

More information

To be able to determine the quadratic character of an arbitrary number mod p (p an odd prime), we. The first (and most delicate) case concerns 2

To be able to determine the quadratic character of an arbitrary number mod p (p an odd prime), we. The first (and most delicate) case concerns 2 Quadratic Reciprocity To be able to determine the quadratic character of an arbitrary number mod p (p an odd prime), we need to be able to evaluate q for any prime q. The first (and most delicate) case

More information

MA/CSSE 473 Day 9. The algorithm (modified) N 1

MA/CSSE 473 Day 9. The algorithm (modified) N 1 MA/CSSE 473 Day 9 Primality Testing Encryption Intro The algorithm (modified) To test N for primality Pick positive integers a 1, a 2,, a k < N at random For each a i, check for a N 1 i 1 (mod N) Use the

More information

Name: Exam Score: /100. Exam 1: Version C. Academic Honesty Pledge

Name: Exam Score: /100. Exam 1: Version C. Academic Honesty Pledge MATH 11008 Explorations in Modern Mathematics Fall 2013 Circle one: MW7:45 / MWF1:10 Dr. Kracht Name: Exam Score: /100. (110 pts available) Exam 1: Version C Academic Honesty Pledge Your signature at the

More information

Crossing Game Strategies

Crossing Game Strategies Crossing Game Strategies Chloe Avery, Xiaoyu Qiao, Talon Stark, Jerry Luo March 5, 2015 1 Strategies for Specific Knots The following are a couple of crossing game boards for which we have found which

More information

Public Key Cryptography Great Ideas in Theoretical Computer Science Saarland University, Summer 2014

Public Key Cryptography Great Ideas in Theoretical Computer Science Saarland University, Summer 2014 7 Public Key Cryptography Great Ideas in Theoretical Computer Science Saarland University, Summer 2014 Cryptography studies techniques for secure communication in the presence of third parties. A typical

More information

Modular Arithmetic: refresher.

Modular Arithmetic: refresher. Lecture 7. Outline. 1. Modular Arithmetic. Clock Math!!! 2. Inverses for Modular Arithmetic: Greatest Common Divisor. Division!!! 3. Euclid s GCD Algorithm. A little tricky here! Clock Math If it is 1:00

More information

Assignment 2. Due: Monday Oct. 15, :59pm

Assignment 2. Due: Monday Oct. 15, :59pm Introduction To Discrete Math Due: Monday Oct. 15, 2012. 11:59pm Assignment 2 Instructor: Mohamed Omar Math 6a For all problems on assignments, you are allowed to use the textbook, class notes, and other

More information

Arithmetic of Remainders (Congruences)

Arithmetic of Remainders (Congruences) Arithmetic of Remainders (Congruences) Donald Rideout, Memorial University of Newfoundland 1 Divisibility is a fundamental concept of number theory and is one of the concepts that sets it apart from other

More information

Grade 7/8 Math Circles February 9-10, Modular Arithmetic

Grade 7/8 Math Circles February 9-10, Modular Arithmetic Faculty of Mathematics Waterloo, Ontario N2L 3G Centre for Education in Mathematics and Computing Grade 7/8 Math Circles February 9-, 26 Modular Arithmetic Introduction: The 2-hour Clock Question: If it

More information

Math 1111 Math Exam Study Guide

Math 1111 Math Exam Study Guide Math 1111 Math Exam Study Guide The math exam will cover the mathematical concepts and techniques we ve explored this semester. The exam will not involve any codebreaking, although some questions on the

More information

Applications of Fermat s Little Theorem and Congruences

Applications of Fermat s Little Theorem and Congruences Applications of Fermat s Little Theorem and Congruences Definition: Let m be a positive integer. Then integers a and b are congruent modulo m, denoted by a b mod m, if m (a b). Example: 3 1 mod 2, 6 4

More information

Public Key Cryptography

Public Key Cryptography Public Key Cryptography How mathematics allows us to send our most secret messages quite openly without revealing their contents - except only to those who are supposed to read them The mathematical ideas

More information

CMPSCI 250: Introduction to Computation. Lecture #14: The Chinese Remainder Theorem David Mix Barrington 24 February 2012

CMPSCI 250: Introduction to Computation. Lecture #14: The Chinese Remainder Theorem David Mix Barrington 24 February 2012 CMPSCI 250: Introduction to Computation Lecture #14: The Chinese Remainder Theorem David Mix Barrington 24 February 2012 The Chinese Remainder Theorem Infinitely Many Primes Reviewing Inverses and the

More information

Numbers (8A) Young Won Lim 6/21/17

Numbers (8A) Young Won Lim 6/21/17 Numbers (8A Copyright (c 2017 Young W. Lim. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version

More information

Divisibility Rules I: Base 10 Number System

Divisibility Rules I: Base 10 Number System Divisibility Rules I: Base 10 Number System Figure 9: HINT (for the joke): What is the number symbol for the amount of dots here in a base 4 number system. After you think about this, if you don t get

More information

Algorithmic Number Theory and Cryptography (CS 303)

Algorithmic Number Theory and Cryptography (CS 303) Algorithmic Number Theory and Cryptography (CS 303) Modular Arithmetic Jeremy R. Johnson 1 Introduction Objective: To become familiar with modular arithmetic and some key algorithmic constructions that

More information

Modular Arithmetic. Kieran Cooney - February 18, 2016

Modular Arithmetic. Kieran Cooney - February 18, 2016 Modular Arithmetic Kieran Cooney - kieran.cooney@hotmail.com February 18, 2016 Sums and products in modular arithmetic Almost all of elementary number theory follows from one very basic theorem: Theorem.

More information

Numbers (8A) Young Won Lim 5/24/17

Numbers (8A) Young Won Lim 5/24/17 Numbers (8A Copyright (c 2017 Young W. Lim. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version

More information

CMPSCI 250: Introduction to Computation. Lecture #14: The Chinese Remainder Theorem David Mix Barrington 4 October 2013

CMPSCI 250: Introduction to Computation. Lecture #14: The Chinese Remainder Theorem David Mix Barrington 4 October 2013 CMPSCI 250: Introduction to Computation Lecture #14: The Chinese Remainder Theorem David Mix Barrington 4 October 2013 The Chinese Remainder Theorem Infinitely Many Primes Reviewing Inverses and the Inverse

More information

MST125. Essential mathematics 2. Number theory

MST125. Essential mathematics 2. Number theory MST125 Essential mathematics 2 Number theory This publication forms part of the Open University module MST125 Essential mathematics 2. Details of this and other Open University modules can be obtained

More information

Introduction to Modular Arithmetic

Introduction to Modular Arithmetic 1 Integers modulo n 1.1 Preliminaries Introduction to Modular Arithmetic Definition 1.1.1 (Equivalence relation). Let R be a relation on the set A. Recall that a relation R is a subset of the cartesian

More information

Grade 6 Math Circles March 8-9, Modular Arithmetic

Grade 6 Math Circles March 8-9, Modular Arithmetic Faculty of Mathematics Waterloo, Ontario N2L 3G Centre for Education in Mathematics and Computing Grade 6 Math Circles March 8-9, 26 Modular Arithmetic Introduction: The 2-hour Clock Question: If its 7

More information

Primitive Roots. Chapter Orders and Primitive Roots

Primitive Roots. Chapter Orders and Primitive Roots Chapter 5 Primitive Roots The name primitive root applies to a number a whose powers can be used to represent a reduced residue system modulo n. Primitive roots are therefore generators in that sense,

More information

Mark Kozek. December 7, 2010

Mark Kozek. December 7, 2010 : in : Whittier College December 7, 2010 About. : in Hungarian mathematician, 1913-1996. Interested in combinatorics, graph theory, number theory, classical analysis, approximation theory, set theory,

More information

= (2 3 ) = c LAMC Beginners Circle September 29, Oleg Gleizer. Warm-up

= (2 3 ) = c LAMC Beginners Circle September 29, Oleg Gleizer. Warm-up LAMC Beginners Circle September 29, 2013 Oleg Gleizer oleg1140@gmail.com Warm-up Problem 1 Simplify the following expressions as much as possible. a. b. 9 3 3 6 = (2 3 ) 4 2 3 2 4 = c. 23 4 2 3 2 4 = d.

More information

DUBLIN CITY UNIVERSITY

DUBLIN CITY UNIVERSITY DUBLIN CITY UNIVERSITY SEMESTER ONE EXAMINATIONS 2013 MODULE: (Title & Code) CA642 Cryptography and Number Theory COURSE: M.Sc. in Security and Forensic Computing YEAR: 1 EXAMINERS: (Including Telephone

More information

LUCAS-SIERPIŃSKI AND LUCAS-RIESEL NUMBERS

LUCAS-SIERPIŃSKI AND LUCAS-RIESEL NUMBERS LUCAS-SIERPIŃSKI AND LUCAS-RIESEL NUMBERS DANIEL BACZKOWSKI, OLAOLU FASORANTI, AND CARRIE E. FINCH Abstract. In this paper, we show that there are infinitely many Sierpiński numbers in the sequence of

More information

Activity 1: Play comparison games involving fractions, decimals and/or integers.

Activity 1: Play comparison games involving fractions, decimals and/or integers. Students will be able to: Lesson Fractions, Decimals, Percents and Integers. Play comparison games involving fractions, decimals and/or integers,. Complete percent increase and decrease problems, and.

More information

Grade 7 & 8 Math Circles October 12, 2011 Modular Arithmetic

Grade 7 & 8 Math Circles October 12, 2011 Modular Arithmetic 1 University of Waterloo Faculty of Mathematics Centre for Education in Mathematics and Computing Grade 7 & 8 Math Circles October 12, 2011 Modular Arithmetic To begin: Before learning about modular arithmetic

More information

Congruences Modulo Small Powers of 2 and 3 for Partitions into Odd Designated Summands

Congruences Modulo Small Powers of 2 and 3 for Partitions into Odd Designated Summands 1 3 47 6 3 11 Journal of Integer Sequences, Vol. 0 (017), Article 17.4.3 Congruences Modulo Small Powers of 3 for Partitions into Odd Designated Summs B. Hemanthkumar Department of Mathematics M. S. Ramaiah

More information

CALCULATING SQUARE ROOTS BY HAND By James D. Nickel

CALCULATING SQUARE ROOTS BY HAND By James D. Nickel By James D. Nickel Before the invention of electronic calculators, students followed two algorithms to approximate the square root of any given number. First, we are going to investigate the ancient Babylonian

More information

SESAME Modular Arithmetic. MurphyKate Montee. March 2018 IN,Z, We think numbers should satisfy certain rules, which we call axioms:

SESAME Modular Arithmetic. MurphyKate Montee. March 2018 IN,Z, We think numbers should satisfy certain rules, which we call axioms: SESAME Modular Arithmetic MurphyKate Montee March 08 What is a Number? Examples of Number Systems: We think numbers should satisfy certain rules which we call axioms: Commutivity Associativity 3 Existence

More information

THE NUMBER OF PERMUTATIONS WHICH FORM ARITHMETIC PROGRESSIONS MODULO m

THE NUMBER OF PERMUTATIONS WHICH FORM ARITHMETIC PROGRESSIONS MODULO m ANALELE ŞTIINŢIFICE ALE UNIVERSITĂŢII AL.I. CUZA DIN IAŞI (S.N.) MATEMATICĂ, Tomul LXI, 2015, f.2 THE NUMBER OF PERMUTATIONS WHICH FORM ARITHMETIC PROGRESSIONS MODULO m BY FLORIAN LUCA and AUGUSTINE O.

More information

Three of these grids share a property that the other three do not. Can you find such a property? + mod

Three of these grids share a property that the other three do not. Can you find such a property? + mod PPMTC 22 Session 6: Mad Vet Puzzles Session 6: Mad Veterinarian Puzzles There is a collection of problems that have come to be known as "Mad Veterinarian Puzzles", for reasons which will soon become obvious.

More information

SOLUTIONS TO PROBLEM SET 5. Section 9.1

SOLUTIONS TO PROBLEM SET 5. Section 9.1 SOLUTIONS TO PROBLEM SET 5 Section 9.1 Exercise 2. Recall that for (a, m) = 1 we have ord m a divides φ(m). a) We have φ(11) = 10 thus ord 11 3 {1, 2, 5, 10}. We check 3 1 3 (mod 11), 3 2 9 (mod 11), 3

More information

Solutions to Exam 1. Problem 1. a) State Fermat s Little Theorem and Euler s Theorem. b) Let m, n be relatively prime positive integers.

Solutions to Exam 1. Problem 1. a) State Fermat s Little Theorem and Euler s Theorem. b) Let m, n be relatively prime positive integers. Solutions to Exam 1 Problem 1. a) State Fermat s Little Theorem and Euler s Theorem. b) Let m, n be relatively rime ositive integers. Prove that m φ(n) + n φ(m) 1 (mod mn). c) Find the remainder of 1 008

More information

n r for the number. (n r)!r!

n r for the number. (n r)!r! Throughout we use both the notations ( ) n r and C n n! r for the number (n r)!r! 1 Ten points are distributed around a circle How many triangles have all three of their vertices in this 10-element set?

More information

SOLUTIONS FOR PROBLEM SET 4

SOLUTIONS FOR PROBLEM SET 4 SOLUTIONS FOR PROBLEM SET 4 A. A certain integer a gives a remainder of 1 when divided by 2. What can you say about the remainder that a gives when divided by 8? SOLUTION. Let r be the remainder that a

More information

The Richard Stockton College of New Jersey Mathematical Mayhem 2013 Group Round

The Richard Stockton College of New Jersey Mathematical Mayhem 2013 Group Round The Richard Stockton College of New Jersey Mathematical Mayhem 2013 Group Round March 23, 2013 Name: Name: Name: High School: Instructions: This round consists of 5 problems worth 16 points each for a

More information

Essentials. Week by. Week

Essentials. Week by. Week Week by Week MATHEMATICS Essentials Grade 5 WEEK 31 Math Trivia Because there are two sets of calendars, for leap years and non-leap years, and seven possible calendars in each set to cover the cases of

More information

A REMARK ON A PAPER OF LUCA AND WALSH 1. Zhao-Jun Li Department of Mathematics, Anhui Normal University, Wuhu, China. Min Tang 2.

A REMARK ON A PAPER OF LUCA AND WALSH 1. Zhao-Jun Li Department of Mathematics, Anhui Normal University, Wuhu, China. Min Tang 2. #A40 INTEGERS 11 (2011) A REMARK ON A PAPER OF LUCA AND WALSH 1 Zhao-Jun Li Department of Mathematics, Anhui Normal University, Wuhu, China Min Tang 2 Department of Mathematics, Anhui Normal University,

More information

The Real Number System and Pythagorean Theorem Unit 9 Part B

The Real Number System and Pythagorean Theorem Unit 9 Part B The Real Number System and Pythagorean Theorem Unit 9 Part B Standards: 8.NS.1 Know that numbers that are not rational are called irrational. Understand informally that every number has a decimal expansion;

More information

Introduction to Number Theory 2. c Eli Biham - November 5, Introduction to Number Theory 2 (12)

Introduction to Number Theory 2. c Eli Biham - November 5, Introduction to Number Theory 2 (12) Introduction to Number Theory c Eli Biham - November 5, 006 345 Introduction to Number Theory (1) Quadratic Residues Definition: The numbers 0, 1,,...,(n 1) mod n, are called uadratic residues modulo n.

More information

Collection of rules, techniques and theorems for solving polynomial congruences 11 April 2012 at 22:02

Collection of rules, techniques and theorems for solving polynomial congruences 11 April 2012 at 22:02 Collection of rules, techniques and theorems for solving polynomial congruences 11 April 2012 at 22:02 Public Polynomial congruences come up constantly, even when one is dealing with much deeper problems

More information

Design and Analysis of RNS Based FIR Filter Using Verilog Language

Design and Analysis of RNS Based FIR Filter Using Verilog Language International Journal of Computational Engineering & Management, Vol. 16 Issue 6, November 2013 www..org 61 Design and Analysis of RNS Based FIR Filter Using Verilog Language P. Samundiswary 1, S. Kalpana

More information

NUMBER THEORY AMIN WITNO

NUMBER THEORY AMIN WITNO NUMBER THEORY AMIN WITNO.. w w w. w i t n o. c o m Number Theory Outlines and Problem Sets Amin Witno Preface These notes are mere outlines for the course Math 313 given at Philadelphia

More information

Square Roots and the Pythagorean Theorem

Square Roots and the Pythagorean Theorem UNIT 1 Square Roots and the Pythagorean Theorem Just for Fun What Do You Notice? Follow the steps. An example is given. Example 1. Pick a 4-digit number with different digits. 3078 2. Find the greatest

More information

Math 127: Equivalence Relations

Math 127: Equivalence Relations Math 127: Equivalence Relations Mary Radcliffe 1 Equivalence Relations Relations can take many forms in mathematics. In these notes, we focus especially on equivalence relations, but there are many other

More information

A New RNS 4-moduli Set for the Implementation of FIR Filters. Gayathri Chalivendra

A New RNS 4-moduli Set for the Implementation of FIR Filters. Gayathri Chalivendra A New RNS 4-moduli Set for the Implementation of FIR Filters by Gayathri Chalivendra A Thesis Presented in Partial Fulfillment of the Requirements for the Degree Master of Science Approved April 2011 by

More information