Multiplication and division Multiples factors and prime numbers

Multiplication and division Multiples, factors and prime numbers Objectives Day 1 Find common multiples and factors. Day 2 Identify prime numbers. Find numbers that have a pair of prime factors. © hamilton-trust. org. uk 1 Year 6

Multiplication and division Multiples, factors and prime numbers Starters Day 1 Factors (pre-requisite skills) Day 2 Double and halve numbers to 100 (simmering skills) © hamilton-trust. org. uk 2 Year 6

Multiplication and division Multiples, factors and prime numbers Starter Factors © hamilton-trust. org. uk 3 Year 6

Multiplication and division Multiples, factors and prime numbers Starter Double and halve numbers to 100 © hamilton-trust. org. uk 4 Year 6

Multiplication and division Multiples, factors and prime numbers Objectives Day 1 Find common multiples and factors. © hamilton-trust. org. uk 5 Year 6

Day 1: Find common multiples and factors. How can we recognise multiples of 9? Some are also multiples of 6. Write three common multiples of 6 and 9 on your whiteboards. © hamilton-trust. org. uk 6 Year 6

Day 1: Find common multiples and factors. See how the common multiples have pink and yellow stripes. Check yours. What is the lowest common multiple? © hamilton-trust. org. uk 7 Year 6

Day 1: Find common multiples and factors. Which of these multiples of 6 are also multiples of 8? What is the smallest common multiple? © hamilton-trust. org. uk 8 Year 6

Day 1: Find common multiples and factors. Work in pairs to list all the factors of each number: one person lists the factors of 18, the other lists the factors of 24. Now look for common factors and ring them. What is the highest common factor? (The biggest number that goes into both 18 and 24. Now work in pairs to list all the factors of 24 and 32. Then ring common factors and find the highest common factor. © hamilton-trust. org. uk 9 Year 6

Challenge © hamilton-trust. org. uk Challenge 10 Year 6

Multiplication and division Multiples, factors and prime numbers Objectives Day 2 Identify prime numbers. Find numbers that have a pair of prime factors. © hamilton-trust. org. uk 11 Year 6

Day 2: Identify prime numbers; Find numbers that have a pair of prime factors. Numbers with only two factors: themselves and 1, are called prime numbers. 2 is the smallest prime, as 1 just has 1 factor not 2. Numbers that have more than themselves and 1 as factors are called composite numbers. 2 3 5 7 Work in pairs to list all the numbers from 2 to 10 which are primes. Now work in pairs to list all the numbers from 10 to 20 which are primes. © hamilton-trust. org. uk 11 13 17 19 Now think of a number between 10 and 20 which has the following factors: 1, itself, two prime numbers. 12 15 Year 6

Challenge © hamilton-trust. org. uk 13 Year 6

Multiplication and division Multiples, factors and prime numbers Well Done! You’ve completed this unit. Objectives Day 1 Find common multiples and factors. Day 2 Identify prime numbers. Find numbers that have a pair of prime factors. © hamilton-trust. org. uk 14 Year 6

Multiplication and Division Problem solving and reasoning questions Which pair of numbers under 20 have the largest number of common factors? What is the highest common factor? Write common multiples of 4 and 6 up to 60. What is the lowest common multiple? Use this information to find the lowest common multiple of 8 and 12. True or false • The lowest common multiple of two prime numbers, a and b is always a x b. • The highest common factor of two multiples of 6 is always 6. © hamilton-trust. org. uk 15 Year 6

Problem solving and reasoning answers Which pair of numbers under 20 have the largest number of common factors? What is the highest common factor? 6 and 12 and 8 and 16 each have four common factors: 6 and 12 have common factors of 1, 2, 3 and 6 (highest). 8 and 16 have common factors of 1, 2, 4 and 8 (highest). Write common multiples of 4 and 6 up to 60. What is the lowest common multiple? Use this information to find the lowest common multiple of 8 and 12. 12 (lowest), 24, 36, 48 and 60. True or false • The lowest common multiple of two prime numbers, a and b is always a x b. • True, since they are prime numbers they will have no other factors so cannot have any other multiples in common. The highest common factor of two multiples of 6 is always 6. False, as long as one of the numbers is a multiple of the othere will be a higher common factor, e. g. 12 and 24. © hamilton-trust. org. uk 16 Year 6