www mathsrevision com Types of Numbers Multiples and

www. mathsrevision. com Types of Numbers Multiples and LCM Factors and HCF Prime numbers Prime Decomposition 10/31/2020 Created by Mr. Lafferty

www. mathsrevision. com Starter Questions 45 o 100 92 o 10/31/2020 Created by Mr. Lafferty o

Types of Numbers www. mathsrevision. com Multiples Learning Intention Success Criteria 1. To explain that Multiples are the times tables 2. To explain how to find the Lowest Common Number. 10/31/2020 Created by Mr. Lafferty 1. To be able to write out multiples 2. Use sets of multiples to identify Lowest Common Multiples

Types of Numbers www. mathsrevision. com Multiples Example 1 : Find the first seven multiples of 3. M 3 = 3, 6 , 9, 12, 15, 18, 21 Example 2 : Find the first five multiples of 4. M 4 = 4, 8 , 12, 16, 20, ……… 10/31/2020 Created by Mr. Lafferty

Types of Numbers www. mathsrevision. com Lowest Common Multiple Smallest Same Number We need to write out multiples in order to find the Lowest Common Multiple. 10/31/2020 Created by Mr. Lafferty

Types of Numbers www. mathsrevision. com Lowest Common Multiple Example : Find the LCM of 3 and 4. M 3 = 3, 6 , 9, 12, 15, ……… M 4 = 4, 8 , 12, 16, 20, ……… LCM = 12 10/31/2020 Created by Mr. Lafferty

Types of Numbers www. mathsrevision. com Revision of Level E Now try Exercise 1 Ch 5 (page 28) 10/31/2020 Created by Mr. Lafferty

www. mathsrevision. com Starter Questions 65 o 150 52 o 10/31/2020 Created by Mr. Lafferty o

Types of Numbers www. mathsrevision. com Using Factors Learning Intention Success Criteria 1. To explain that a factor divides into a number with no remainder 1. To identify factors using factor pairs 2. To explain how to find Highest Common Factors 2. Find HCF for two numbers by comparing factors. 10/31/2020 Created by Mr. Lafferty

Types of Numbers www. mathsrevision. com Factors Example : Find the factors of 56. Always divide by 1 and find its pair F 56 = 1 and 56 From 2 find other factors and their pairs 2 and 28 4 and 14 6 and 10/31/2020 Created by Mr. Lafferty 8

Types of Numbers www. mathsrevision. com Highest Common Factor Largest Same Number We need to write out all factor pairs in order to find the Highest Common Factor. 10/31/2020 Created by Mr. Lafferty

Types 5 of Numbers www. mathsrevision. com Highest Common Factor Example : Find the HCF of 8 and 12. F 8 = 1 and 8 F 12 = 1 and 12 2 and 4 2 and 6 3 and 4 HCF = 4 10/31/2020 Created by Mr. Lafferty

Types of Numbers www. mathsrevision. com Revision of Level E Now try Exercise 2 Ch 5 (page 30) 10/31/2020 Created by Mr. Lafferty

www. mathsrevision. com Starter Questions 4 cm 5 cm 10/31/2020 Created by Mr. Lafferty

Types of Numbers www. mathsrevision. com Prime Numbers Learning Intention Success Criteria 1. To explain what a prime number is and to find all the prime numbers from 1 and 200. 10/31/2020 Created by Mr. Lafferty 1. To know the meaning of the term Prime Number. 2. Find all prime between 1 and 200.

Types of Numbers www. mathsrevision. com Prime Numbers Definition : A prime number is a number with exactly 2 factors. Example : Is 7 a prime number. Explain? Yes, only two factors 1, 7 Example : Is 10 a prime number. Explain? No, more than two factors 1, 2, 5, 10 10/31/2020 Created by Mr. Lafferty

Strike the two’s, strike three’s the Sieve of Eratosthenes 25 primes Below 100 when the multiples sublime, the numbers that remain are prime!

Use the method of Eratosthenes to find all primes below 200 What is the largest prime < 200? 46 primes below 200

Range 0 – 1000 – 2000 – 3000 – 4000 - 5000 - 6000 - 7000 – 8000 - 9000 – 10 000 – 11 000 – 12 000 Number of Primes 168 135 127 120 119 114 117 107 110 112 106 103 ?

Worksheet – www. mathsrevision. com Strike the two’s, strike three’s the Sieve of Eratosthenes when the multiples sublime, the numbers that remain are prime!

Types of Numbers www. mathsrevision. com Revision of Level E Now try Exercise 3 Ch 5 (page 32) 10/31/2020 Created by Mr. Lafferty

www. mathsrevision. com Starter Questions 5 cm 8 cm 119 10/31/2020 Created by Mr. Lafferty o

Types of Numbers www. mathsrevision. com Prime Decomposition Learning Intention Success Criteria 1. To explain what prime decomposition is and use it to decompose numbers into a product of prime numbers only. 10/31/2020 Created by Mr. Lafferty 1. To know the meaning of the term prime decomposition. 2. Decompose numbers to a product of prime only.

Types of Numbers www. mathsrevision. com Prime Decomposition A number is either Prime or Composite. (except for 0) If it is composite, like 12, it can always be expressed as a “product of primes” Example : Express 12 as a “product of primes” 12 12 3 All Prime ! 10/31/2020 3 =3 x 4 4 2 2 Created by Mr. Lafferty =3 x 2 x 2

Types of Numbers Prime Decomposition www. mathsrevision. com Example : Express 18 as a “product of primes” 18 18 3 All Prime ! 10/31/2020 3 =3 x 6 6 3 2 Created by Mr. Lafferty =3 x 3 x 2

Types of Numbers www. mathsrevision. com Revision of Level E Now try Exercise 4 Ch 5 (page 35) 10/31/2020 Created by Mr. Lafferty