1. Investigating Factors of numbers

2. Investigate the factors of the following numbers Prime numbers are numbers that have exactly two different factors ( no more / no less) They have 1 and themselves No.FactorsPrimeNo.FactorsPrime 111 212 313 414 515 616 717 818 919 1020

3. No.FactorsNo.Factors 111 212 313 414 515 616 717 818 919 1020 1 1, 2 1, 3 1, 2, 4 1, 5 1, 2, 3, 6 1, 7 1, 2, 4, 8 1, 3, 9 1, 2, 5, 10 1, 11 1, 2, 3, 4, 6, 12 1, 2,7, 14 1, 13 1, 3, 5, 15 1, 2, 4,8,16 1, 17 1, 2, 3, 6, 9, 18 1, 19 1, 2, 4, 5, 10, 20 No Yes No Yes Prime Prime numbers are numbers that have exactly two different factors ( no more / no less) They have 1 and themselves Prime numbers are numbers that have exactly two different factors ( no more / no less) They have 1 and themselves

4. The first fifteen Prime numbers are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47 Prime factors of a number Find the factors of a number and say which are prime e.g1 Find the prime factors of(i) 10 and (ii) 16 1 x 10 2 x 5 Prime factors of 10 are 2 and 5 16 1 x 16 2 x 8 `Prime factor of 16 is 2 10 4 x 4

5. 10 1 Writing a number as a product of Prime factors Divide the number by one of its prime factors (generally start with the smallest) Write the answer below Divide this again by the next prime factor Keep going until your final answer is 1 All the factors used multiply together to give the original number e.g2 Write the following as a product of their prime factors (i) 10 (ii) 16(iii) 65 2 10 = 2 x 5 5 5 16 2 8 2 4 1 2 2 2 16 = 2 x 2 x 2 x 2 65 5 13 1 65= 5 x 13