The second lesson in a series of work on level 6+ maths KS2 Skills Factor trees starter M A T H S MIXED STARTER M A T H S MIXED STARTER Write the smallest multiple of three that is bigger than one hundred Put the squares above in size order (smallest to largest). Explain your solution. What number is five cubed? The second lesson in a series of work on level 6+ maths Find the value of a, b and c from the diagram LO: To construct prime factor trees

The second lesson in a series of work on level 6+ maths Number theory: Factor trees 14/11/2018 Core: will be able to identify and use prime numbers. Challenge: will be able to use factor trees to express a number as a product of its primes Aspire: to use known facts Vivo Star: Display a high level of understanding including how all values can be expressed using prime factors. Keywords: Factor, Prime, Product and Indices The second lesson in a series of work on level 6+ maths LO: To construct prime factor trees

The second lesson in a series of work on level 6+ maths Powers M A T H S ACQUIRE FLUENCY 12 22 32 42 52 62 72 82 92 102 13 23 33 43 53 The second lesson in a series of work on level 6+ maths Can you find all the factors of 120 which are also prime numbers? Calculate the following (1) 33 x 22 (2) 12 x 3 x 52 (3) 3 x 22 x 7 (4) 3 x 23 x 5 LO: To construct prime factor trees

The second lesson in a series of work on level 6+ maths Prime factor trees M A T H S TALK ABOUT IT To find the prime factorisation of a number is to express it as a product of prime numbers. ? 30=2×3×5 12= 2 2 ×3 ? ? 120 = 2 3 ×3×5 We can use a ‘tree’ to help us with the working. For each number, find two numbers the multiply to give it. The second lesson in a series of work on level 6+ maths 20 6 4 5 2 3 If you get to a prime, we can’t branch out further, so we have a ‘leaf’. It’s helpful to circle the leaves. 2 2 LO: To construct prime factor trees

The second lesson in a series of work on level 6+ maths Factor trees, factors and roots M A T H S HAVE A GO These numbers have been written as a product of primes. Find each number By drawing a tree of otherwise, find prime factorisations (in index form) for the following numbers. 28= 𝟐 𝟐 ×𝟕 75=𝟑× 𝟓 𝟐 1000= 𝟐 𝟑 × 𝟓 𝟑 378=𝟐× 𝟑 𝟑 ×𝟕 396= 𝟐 𝟐 × 𝟑 𝟐 ×𝟏𝟏 1755= 𝟑 𝟐 × 𝟓 𝟐 ×𝟏𝟑 432= 𝟐 𝟒 × 𝟑 𝟑 ? (1) 23 x 32 (2) 22 x 5 x 72 (3) 3 x 52 x 7 (4) 2 x 33 x 5 ? ? ? The second lesson in a series of work on level 6+ maths ? ? ? What are the factors of 2 5 ? 𝟏, 𝟐,𝟒,𝟖,𝟏𝟔,𝟑𝟐 Write 36 as a product of its primes. Explain why 36 is a square number and use your prime factorisation to square root 36. ? LO: To construct prime factor trees

The second lesson in a series of work on level 6+ maths Known facts M A T H S SUM IT UP 2 1 225 = 2 x 3 x 5 = 2 2 2 Given that 450 = 2 x 3 x 5 2 2 The second lesson in a series of work on level 6+ maths 4 Extension: Explain why 900 is a square number and find it’s square root 3 150 = 2 x 3 x 5 = 2 2 3 LO: To construct prime factor trees