Prime Factorization with Unifix Cube Arrays Math Grade 6 by Beckey Townsend

2 3 ? What is the rule?

? 12 12 2 6 2 3 2 x 2 x 3 = 12 22 x 31 = 12

Working with more prime numbers. 5 Working with more prime numbers. 7 ? 70 5 = Red --- Five little monkeys jumping on a bed, one fell off and hit his head (red, bed, head) 7 = White ---- Snow White and the 7 dwarves ? 30

70 70 70 7 10 5 2 7 x 5 x 2 = 70

? 30 30 30 2 15 3 5 2 x 3 x 5 = 30

Write prime factor equations for these Unifix arrays: 2 1 x 5 1 x 3 1 x 7 1 = ? 1 2 3 x 5 1 = ? 2 2 2 x 3 3 x 7 2 = ? 3 2 3 x 3 2 x 5 1 x 7 1 = ? 4

How to do Prime Factorization Watch this video demonstration. https://www.youtube.com/watch?v=9YOuETNDqik 1 PRACTICE by factoring the following numbers: 48 81 125 72 200 24 36 180 63 2 Another presentation Reteach = https://www.youtube.com/watch?v=tW97UU01ShY

CHECK the practice problems National Library of Virtual Manipulatives http://nlvm.usu.edu/en/nav/topic_t_1.html 3 x 3 x 3 x 3 3 4 = 81 5 x 5 x 5 5 3 = 125 2 x 3 x 2 x 2 x 2 2 4 x 3 1 = 48 3 x 3 x 2 x 2 x 2 3 2 x 2 3 = 72 2 x 5 x 5 x 2 x 2 2 3 x 5 2 = 200 3 x 2 x 2 x 2 3 1 x 2 3 = 24 2 x 3 x 2 x 3 2 2 x 3 2 = 36 3 x 3 x 5 x 2 x 2 3 2 x 5 1 x 2 2 = 180 3 x 3 x 7 3 2 x 7 1 = 63

Prime Factorization (Algorithm) WHY? Use your own words to describe HOW to factor the number 42 and WHY it works.

Textbook Section 1.2 Prime Factorization Vocabulary Review: See page 16 Two Methods: See page 17 Prime Numbers: See Practice #1, page 18 number array. Copy into math journal and circle the prime numbers. Practice with larger numbers: Work together page 18 #13-18, #20-21 http://nlvm.usu.edu/en/nav/topic_t_1.html Independent review & practice: On rotation day complete textbook page 18 #2-23 “Practice 1.2” Track A = even numbers only Track B = odd numbers + 22 Track C = #14-23

EXIT TICKET TODAY WE LEARNED … … use divisibility rules and multiplication facts to break a number down into its prime factors. … how to explain and justify the prime factorization process. … to practice fluency for prime factorization. Grab your student assignment sheet, review worksheet, and your math journal slip. Complete the “exit ticket” assignment and turn it in to the teacher. Continue working on the rest of the assignment sheet. If it is not finished in class, then it must be completed for homework.