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

2. 2 3 ?
What is the rule?

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

4. 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

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

6. ? 30 30 30 2 15 3 5
2 x 3 x 5 = 30

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

8. How to do Prime Factorization
Watch this video demonstration. 1
PRACTICE by factoring the following numbers: 2
Another presentation
Reteach =

9. CHECK the practice problems
National Library of Virtual Manipulatives
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 = 48
3 x 3 x 2 x 2 x 2
3 2 x = 72
2 x 5 x 5 x 2 x 2
2 3 x = 200
3 x 2 x 2 x 2
3 1 x = 24
2 x 3 x 2 x 3
2 2 x = 36
3 x 3 x 5 x 2 x 2
3 2 x x = 180
3 x 3 x 7
3 2 x = 63

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

11. 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
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

12. 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.