6th Grade Math Textbook, Progress

Prime Factorization Using Divisibility Rules

You can use the divisibility rules to help you find the

prime factorization of larger numbers.

Find the prime factorization and write in exponential form.

12. 32 13. 24 14. 50 15. 125 16. 63


13. 71 18. 44 19. 60 20. 100 21. 96

Find the prime factorization of 9450.

ends in 0; divide by 10

digit sum is 18; divide by 9

ends in 5; divide by 5

digit sum is 3; divide by 3

all prime numbers

So, the prime factorization of 9450 is 2
 33 
 52 
7.

9

945

21

9450

2 5 3 3 5

(^2)




5
(^2)
(^5)

105
3 3 5
3 7
10
Find the prime factorization. Use the divisibility rules
and a factor tree to help.

22. 95 23. 114 24. 153 25. 390 26. 504


23. 189 28. 225 29. 540 30. 1215 31. 2916

Solve for yto complete the prime factorization.

32. 2
    y
    3  12 33. 2 y 82 34. 117  32
    y


33. 23
    y 88 36. 110 y
    5
    11 37. 22
    y
    5  60

Make two different factor trees for each number.

Then write the prime factorization for each.

38. 70 39. 99 40. 120 41. 40


39. 48 43. 150 44. 84 45. 54

Composite.

Factor again.

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