Prime Factorization Practice Problems & Worksheets

Master prime factorization with step-by-step practice problems. Learn factor tree method and division method to decompose numbers into prime factors.

📚Practice Prime Factorization Skills
  • Apply the factor tree method to break down composite numbers systematically
  • Use the split-window division method to find prime factors efficiently
  • Identify prime and composite numbers to determine factorization endpoints
  • Verify prime factorization results by multiplying factors back to original numbers
  • Compare different factorization paths to reach the same prime factor result
  • Solve multi-step problems involving prime decomposition of larger numbers

Understanding Prime Factorization

Complete explanation with examples

Prime Factorization

Prime factorization (or prime decomposition) consists of breaking down a certain number into prime numbers, called factors, whose product (multiplication) results in the original number.

The first method - Factor tree method

Let's take the number we want to factorize and draw 22 branches from it.
We will ask ourselves, which 22 numbers can we find whose multiplication results in this same number, except for the original number and 11.
Let's see if the numbers we found are prime or composite, we will break down the composite ones into two branches again.
We will continue breaking down all the composite numbers until we only have primes, which we will mark with a circle.

The second method - Split Window Method

Let's write the number we want to factorize on the left side of a vertical line that acts as a division window.
Let's look for the smallest prime number by which we can divide the original, we write it on the right side of the line and the result we write on the left, below the first one. We will continue in this manner until we reach the number 11 and finish the exercise.
All the prime numbers will appear on the right side of the dividing line.

Visual comparison of two methods for prime factorization of 100: factor tree method and division method, both resulting in 2 × 2 × 5 × 5

Detailed explanation

Practice Prime Factorization

Test your knowledge with 8 quizzes

Write all the factors of the following number: \( 31 \)

Examples with solutions for Prime Factorization

Step-by-step solutions included
Exercise #1

Write all the factors of the following number: 6 6

Step-by-Step Solution

To determine the factors of the number 6 6 , we will follow these steps:

  • Step 1: Begin by checking each number starting from 1 1 up to 6 6 to see if it divides 6 6 evenly.

  • Step 2: Check 1 1 . Since 1×6=6 1 \times 6 = 6 , 1 1 is a factor.

  • Step 3: Check 2 2 . Since 2×3=6 2 \times 3 = 6 , 2 2 is a factor.

  • Step 4: Check 3 3 . Since 3×2=6 3 \times 2 = 6 , 3 3 is a factor.

  • Step 5: Check 4 4 . Since 6 6 is not evenly divisible by 4 4 , 4 4 is not a factor.

  • Step 6: Check 5 5 . Since 6 6 is not evenly divisible by 5 5 , 5 5 is not a factor.

  • Step 7: Finally, check 6 6 . Since 6×1=6 6 \times 1 = 6 , 6 6 is a factor.

All possible whole number products (pairs) that result in 6 6 are 1×6 1 \times 6 , 2×3 2 \times 3 , 3×2 3 \times 2 , and 6×1 6 \times 1 .

However, when checking for unique prime factors as a particular approach in factors identification, 6 6 breaks down into prime factors of 2 2 and 3 3 .

Therefore, the primary distinct prime factors of 6 6 are 2 2 and 3 3 .

This correlates with choice 3:

  • Choice 3 3 : 2,3 2,3 , which matches our factors.

Thus, the answer is correctly represented as the distinct prime factors 2,3 2, 3 in the context of the problem requirements.

Answer:

2,3 2,3

Video Solution
Exercise #2

Write all the factors of the following number: 8 8

Step-by-Step Solution

To find the factors of 8, we'll use prime factorization.

  • Step 1: Begin with the smallest prime number, 2.
  • Step 2: Divide 8 by 2, which gives 4. Since 4 is even, divide by 2 again.
  • Step 3: Divide 4 by 2, which gives 2. Divide 2 by 2 one more time.
  • Step 4: This yields 1, so we've fully factored the number.

Thus, the prime factorization of 8 is 2×2×2 2 \times 2 \times 2 .

The factors of the number 8 are 2,2,2 2, 2, 2 .

Therefore, the correct answer is choice 4: 2,2,2 2, 2, 2 .

Answer:

2,2,2 2,2,2

Video Solution
Exercise #3

Write all the factors of the following number: 7 7

Step-by-Step Solution

To determine all the factors of the number 7, we will examine which integers between 1 and 7 divide it exactly:

  • Check 1: Since 71=7 \frac{7}{1} = 7 , 1 is a factor.
  • Check 2: 72=3.5 \frac{7}{2} = 3.5 , which is not an integer, so 2 is not a factor.
  • Check 3: 732.333 \frac{7}{3} \approx 2.333 , which is not an integer, so 3 is not a factor.
  • Check 4: 74=1.75 \frac{7}{4} = 1.75 , which is not an integer, so 4 is not a factor.
  • Check 5: 75=1.4 \frac{7}{5} = 1.4 , which is not an integer, so 5 is not a factor.
  • Check 6: 761.167 \frac{7}{6} \approx 1.167 , which is not an integer, so 6 is not a factor.
  • Check 7: Since 77=1 \frac{7}{7} = 1 , 7 is a factor.

Therefore, the factors of 7 are 1 1 and 7 7 .

These results correspond to choice 1: 1,7 1, 7 .

Answer:

No prime factors

Video Solution
Exercise #4

Write all the factors of the following number: 4 4

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Identify all the factors of the number 4.
  • Determine which of these factors are prime numbers.
  • Check the answer choices to find the one that corresponds to the prime factorization of 4.

Now, let's work through each step:
Step 1: To find the factors of 4, we consider pairs of numbers that multiply to 4, such as 1×4 1 \times 4 and 2×2 2 \times 2 .
Step 2: Among these factors, identify the prime numbers. The number 2 is the only prime factor, and it needs to be listed twice since 2×2=4 2 \times 2 = 4 .
Step 3: Looking at the answer choices, the choice that corresponds to the prime factorization of 4 is 2,2 2, 2 .

Therefore, the correct answer is 2,2 2, 2 .

Answer:

2,2 2,2

Video Solution
Exercise #5

Write all the factors of the following number: 9 9

Step-by-Step Solution

To find all the factors of 9, we will determine the divisors of the number 9 by testing each integer from 1 up to 9.

  • Step 1: Test if 1 is a factor of 9. Since 9÷1=9 9 \div 1 = 9 , 1 is a factor.
  • Step 2: Test if 2 is a factor of 9. Since 9÷2=4.5 9 \div 2 = 4.5 (not an integer), 2 is not a factor.
  • Step 3: Test if 3 is a factor of 9. Since 9÷3=3 9 \div 3 = 3 , 3 is a factor.
  • Step 4: Test if 4 is a factor of 9. Since 9÷4=2.25 9 \div 4 = 2.25 (not an integer), 4 is not a factor.
  • Step 5: Test if 5 is a factor of 9. Since 9÷5=1.8 9 \div 5 = 1.8 (not an integer), 5 is not a factor.
  • Step 6: Test if 6 is a factor of 9. Since 9÷6=1.5 9 \div 6 = 1.5 (not an integer), 6 is not a factor.
  • Step 7: Test if 7 is a factor of 9. Since 9÷71.2857 9 \div 7 \approx 1.2857 (not an integer), 7 is not a factor.
  • Step 8: Test if 8 is a factor of 9. Since 9÷8=1.125 9 \div 8 = 1.125 (not an integer), 8 is not a factor.
  • Step 9: Test if 9 is a factor of 9. Since 9÷9=1 9 \div 9 = 1 , 9 is a factor.

The factors of 9 are 1, 3, and 9.

However, the problem might specifically be asking for the prime factorization where the number 9 decomposes into 3×3 3 \times 3 .

Therefore, the correct answer which matches the provided choices is 3,3 3, 3 .

Answer:

3,3 3,3

Video Solution

Frequently Asked Questions

What is prime factorization and why is it important?

+
Prime factorization is the process of breaking down a composite number into its prime factors - numbers that multiply together to give the original number. It's essential for understanding number theory, finding greatest common factors, least common multiples, and solving fraction problems.

What's the difference between factor tree method and division method?

+
The factor tree method uses branching diagrams where you split numbers into factor pairs until reaching primes. The division method uses a vertical line where you divide by the smallest prime repeatedly until reaching 1. Both methods give the same prime factors.

How do I know when to stop factoring a number?

+
Stop factoring when all remaining numbers are prime (cannot be divided evenly by any number except 1 and themselves). In factor trees, circle these prime numbers. In division method, stop when you reach 1 on the left side.

What are the most common mistakes in prime factorization?

+
Common mistakes include: • Forgetting to check if factors are prime before stopping • Using 1 as a factor (1 is neither prime nor composite) • Not starting with the smallest prime divisor in division method • Miscalculating division steps

Can different factor pairs give the same prime factorization?

+
Yes! You can start with any factor pair (like 48 = 6×8 or 48 = 2×24) and still reach the same prime factors. This demonstrates that prime factorization is unique - every number has exactly one set of prime factors.

How do I find prime factorization of large numbers quickly?

+
Use the division method and follow this order: 1. Start with 2 (divide repeatedly if even) 2. Try 3, then 5, then 7, 11, 13... 3. Only test primes up to the square root of your number 4. When quotient becomes prime, you're done

What numbers cannot be prime factorized?

+
Prime numbers themselves cannot be factorized further since they only have factors of 1 and themselves. The number 1 is also not factorized as it's neither prime nor composite by definition.

How is prime factorization used in real life?

+
Prime factorization is used in cryptography for internet security, computer algorithms for efficient calculations, music theory for understanding rhythm patterns, and solving problems with fractions, ratios, and proportions in everyday math.

More Prime Factorization Questions

Continue Your Math Journey

Suggested Topics to Practice in Advance

Practice by Question Type