Prime Factorization

Factors 1 x 4 = 4 and 2 x 2 = 4 1 x 6 = 6 and 2 x 3 = 6 are numbers we can multiply together to get another number. What are the factors of 4: 1 x 4 = 4 and 2 x 2 = 4 What are the factors of 6: 1 x 6 = 6 and 2 x 3 = 6

Which ones are the “Prime Factors”?? is finding which prime numbers multiply together to make the original number. Prime Factorization - So the factors of 4 were?? 1 x 4 = 4 and 2 x 2 = 4 Which ones are the “Prime Factors”?? 2 x 2

Which ones are the “Prime Factors”?? The factors of 6 were?? 1 x 6 = 6 and 2 x 3 = 6 Which ones are the “Prime Factors”?? 2 x 3

Stand quietly behind desk if finished! 30 sec CHALLENGE! Stand quietly behind desk if finished! Which of the following numbers are PRIME? 3, 6, 10, 7, 14, 2, 15, 17, 21, 26, 30, 11, 18, 23, 25, 36, 32, 42, 56, 29, 63, 37, 99, 100, 41, 54, 1, 27, 31, 77

We are going to use a factor tree to find the ‘prime factors’ 1 x 12 2 x 6 3 x 4 12 What are 2 factors of 12? Does 1 x 12 really help? 3 x 4 Prime Not Prime 2 x 2 Prime Prime Prime Factors = 2 x 2 x 3 or 2² x 3

36 Lets try another one: What are some of the factors of 36? 1 x 36 Prime 3 x 12 Not prime Prime 3 x 4 Not Prime Prime 2 x 2 prime Prime factors = 2 x 2 x 3 x 3 Or 2² x 3²

More Practice: 45 32 50 64 47 5 x 9 4 x 8 5 x 10 8 x 8 1 x 47 3 x 3 2 x 2 2 x 4 2 x 5 2 x 4 2 x 4 2 x 2 2 x 2 2 x 2 3x3x5 2x2x2x2x2 2x5x5 2x2x2x2x2x2 47 3² x 5 25 2 x 5² 26