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Prime Factorization

Learn to break down numbers into their prime factors

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Prime Factorization

Prime Numbers

A prime number is a whole number greater than 1 that has exactly two factors: 1 and itself.

Examples of prime numbers: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29...

Note: 2 is the only even prime number!

Composite Numbers

A composite number is a whole number greater than 1 that has more than two factors.

Examples: 4, 6, 8, 9, 10, 12, 14, 15, 16...

Prime Factorization

Prime factorization means writing a number as a product of prime numbers.

Example: 24=2×2×2×3=23×324 = 2 \times 2 \times 2 \times 3 = 2^3 \times 3

Methods

  1. Factor Tree Method: Break down the number step by step
  2. Division Method: Divide by prime numbers starting from 2

Why It's Useful

Prime factorization helps us:

  • Find the Greatest Common Factor (GCF)
  • Find the Least Common Multiple (LCM)
  • Simplify fractions

📚 Practice Problems

1Problem 1easy

❓ Question:

Find the prime factorization of 18.

💡 Show Solution

Solution:

Using a factor tree: 18=2×918 = 2 \times 9 9=3×39 = 3 \times 3

So: 18=2×3×3=2×3218 = 2 \times 3 \times 3 = 2 \times 3^2

Answer: 18=2×3218 = 2 \times 3^2

2Problem 2easy

❓ Question:

Find the prime factorization of 18.

💡 Show Solution

Solution:

Using a factor tree: 18=2×918 = 2 \times 9 9=3×39 = 3 \times 3

So: 18=2×3×3=2×3218 = 2 \times 3 \times 3 = 2 \times 3^2

Answer: 18=2×3218 = 2 \times 3^2

3Problem 3medium

❓ Question:

Is 37 a prime number or composite number? Explain.

💡 Show Solution

Solution:

Check if any prime numbers less than 37 divide it evenly:

  • 37÷2=18.537 \div 2 = 18.5 (not whole)
  • 37÷3=12.33...37 \div 3 = 12.33... (not whole)
  • 37÷5=7.437 \div 5 = 7.4 (not whole)
  • We only need to check up to 37≈6\sqrt{37} \approx 6

Since no prime numbers divide 37 evenly, it has no factors other than 1 and 37.

Answer: 37 is a prime number

4Problem 4medium

❓ Question:

Is 37 a prime number or composite number? Explain.

💡 Show Solution

Solution:

Check if any prime numbers less than 37 divide it evenly:

  • 37÷2=18.537 \div 2 = 18.5 (not whole)
  • 37÷3=12.33...37 \div 3 = 12.33... (not whole)
  • 37÷5=7.437 \div 5 = 7.4 (not whole)
  • We only need to check up to 37≈6\sqrt{37} \approx 6

Since no prime numbers divide 37 evenly, it has no factors other than 1 and 37.

Answer: 37 is a prime number

5Problem 5hard

❓ Question:

Find the prime factorization of 180.

💡 Show Solution

Solution:

Using the division method: 180÷2=90180 \div 2 = 90 90÷2=4590 \div 2 = 45 45÷3=1545 \div 3 = 15 15÷3=515 \div 3 = 5 5÷5=15 \div 5 = 1

So: 180=2×2×3×3×5=22×32×5180 = 2 \times 2 \times 3 \times 3 \times 5 = 2^2 \times 3^2 \times 5

Answer: 180=22×32×5180 = 2^2 \times 3^2 \times 5

6Problem 6hard

❓ Question:

Find the prime factorization of 180.

💡 Show Solution

Solution:

Using the division method: 180÷2=90180 \div 2 = 90 90÷2=4590 \div 2 = 45 45÷3=1545 \div 3 = 15 15÷3=515 \div 3 = 5 5÷5=15 \div 5 = 1

So: 180=2×2×3×3×5=22×32×5180 = 2 \times 2 \times 3 \times 3 \times 5 = 2^2 \times 3^2 \times 5

Answer: 180=22×32×5180 = 2^2 \times 3^2 \times 5

Explain using:

📌 Related Topics in Number Operations

❓ Frequently Asked Questions

What is Prime Factorization?▾
Learn to break down numbers into their prime factors
How can I study Prime Factorization effectively?▾
Start by reading the study notes and working through the examples on this page. Then use the flashcards to test your recall. Practice with the 6 problems provided, checking solutions as you go. Regular review and active practice are key to retention.
Is this Prime Factorization study guide free?▾
Yes — all study notes, flashcards, and practice problems for Prime Factorization on Study Mondo are free to access. No account is needed.
What course covers Prime Factorization?▾
Prime Factorization is part of the Grade 6 Math course on Study Mondo, specifically in the Number Operations section. You can explore the full course for more related topics and practice resources.
Are there practice problems for Prime Factorization?▾
Yes, this page includes 6 practice problems with detailed solutions. Each problem includes a step-by-step explanation to help you understand the approach.