Puzzle Can you draw this without going over the same line twice and without taking your pen off the page?

Multiples, factors and primes To revise the definitions of multiples factors and primes To understand the meanings of HCF and LCM To learn an algorithm to computes the HCF and LCM

Recap- multiples Write down the first five multiples of: a)3 b)5 c)4 d)11 e)9 a)3, 6, 9, 12, 15 b)5, 10, 15, 20, 25, 30 c)4, 8, 12, 16, 20 d)11, 22, 33, 44, 55 e)9, 18, 27, 36, 45

Definition Product – An answer to a multiplication problem. 7 x 8 = 56 Product

Definition Factor – a number that divides into another number WITHOUT a remainder 7 x 8 = 56 Factors – because 56 ÷ 8 = 7

What are the other factors of 56? 1, 2, 4, 7, 8, 14, 38, 56

Definition Prime Number – a number that has exactly two factors, itself and 1. What are the first ten prime numbers? 2, 3, 5, 7, 11, 13, 17, 19, 23, 27

Prime factor decomposition Write the number 36 as the product of its prime factors = 2 x 2 x 3 x 3 36 = 2 2 x 3 2

Prime factor decomposition Write the number 28 as the product of its prime factors = 2 x 2 x 7 28 = 2 2 x 7 2

Prime factor decomposition

HCF and LCM HCF is Highest Common Factor LCM is Lowest Common Multiple The HCF of 18 and 24 is… 6 The LCM of 12 and 15 is… 60

1. Use a factor tree to help you find the Prime Factors 2.Then a Venn Diagram to help you find the HCF and LCM Find the HCF and LCM of 24 and 60

FACTOR TREES

24 60 Venn Diagram 24 = 2 x 2 x 2 x 3 60 = 2 x 2 x 3 x HCF = 2 x 2 x 3 = 12 LCM = 2 x 2 x 2 x 3 x 5 = 120 HCF is the region of intersection 2 x 2 x 3 = 12 LCM is all the numbers in the circles multiplied together 2 x 2 x 2 x 3 x 5=120