Prime Factorization | Worksheet - Free Printable
Educational worksheet: Prime Factorization | Worksheet. Download and print for classroom or home learning activities.
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Step-by-step solution for: Prime Factorization | Worksheet
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Show Answer Key & Explanations
Step-by-step solution for: Prime Factorization | Worksheet
Let's solve the Prime Factorization worksheet step by step. The goal is to find the prime factorization of each given number, breaking it down into a product of prime numbers. We’ll use factor trees or repeated division by primes, and write the final answer in exponential form if possible.
---
- A prime number is a number greater than 1 that has no positive divisors other than 1 and itself.
- Prime factorization means expressing a number as a product of prime numbers.
- We can use a factor tree method: divide the number by the smallest prime until all factors are prime.
---
We’ll go through each number one by one.
---
They show:
```
24
/ \
6 4
/ \ / \
3 2 2 2
```
So, the prime factors are:
2 × 2 × 2 × 3 → which is 2³ × 3
✔ Correct.
---
Now let’s do the rest:
---
Start dividing by smallest prime:
- 50 ÷ 2 = 25 → 2 is prime
- 25 ÷ 5 = 5 → 5 is prime
- 5 ÷ 5 = 1
So, prime factors: 2 × 5 × 5 → 2 × 5²
✔ Answer: 2 × 5²
---
- 56 ÷ 2 = 28
- 28 ÷ 2 = 14
- 14 ÷ 2 = 7 → 7 is prime
So, prime factors: 2 × 2 × 2 × 7 → 2³ × 7
✔ Answer: 2³ × 7
---
- 42 ÷ 2 = 21
- 21 ÷ 3 = 7 → 7 is prime
So, prime factors: 2 × 3 × 7
✔ Answer: 2 × 3 × 7
---
- 27 ÷ 3 = 9
- 9 ÷ 3 = 3
- 3 ÷ 3 = 1
So, prime factors: 3 × 3 × 3 → 3³
✔ Answer: 3³
---
- 66 ÷ 2 = 33
- 33 ÷ 3 = 11 → 11 is prime
So, prime factors: 2 × 3 × 11
✔ Answer: 2 × 3 × 11
---
- 43 is a prime number (only divisible by 1 and 43)
✔ Answer: 43 (already prime)
---
- 48 ÷ 2 = 24
- 24 ÷ 2 = 12
- 12 ÷ 2 = 6
- 6 ÷ 2 = 3 → 3 is prime
So, prime factors: 2 × 2 × 2 × 2 × 3 → 2⁴ × 3
✔ Answer: 2⁴ × 3
---
- 70 ÷ 2 = 35
- 35 ÷ 5 = 7 → 7 is prime
So, prime factors: 2 × 5 × 7
✔ Answer: 2 × 5 × 7
---
Wait! 48 appears twice? Let's check:
Looking at the image layout:
- Row 1: 50, 56
- Row 2: 42, 27
- Row 3: 66, 43
- Row 4: 48, 70
- Row 5: 48, 70 ← Wait, 48 and 70 again?
But actually, looking at the structure:
It seems like there are two rows of numbers:
- First row: 50, 56
- Second: 42, 27
- Third: 66, 43
- Fourth: 48, 70
- Fifth: 48, 70 → possibly typo or repeat?
But likely, the last two boxes are meant to be separate entries. Let’s assume they are:
- 48 (again) and 70 (again), but maybe it's a mistake.
But since both are already solved, we'll just list them again.
Wait — actually, in the image, the bottom row says:
> 48 70
So only one instance of each.
But earlier we did 48 and 70 already.
So now, let’s double-check all:
---
| Number | Prime Factorization |
|--------|---------------------|
| 50 | 2 × 5² |
| 56 | 2³ × 7 |
| 42 | 2 × 3 × 7 |
| 27 | 3³ |
| 66 | 2 × 3 × 11 |
| 43 | 43 (prime) |
| 48 | 2⁴ × 3 |
| 70 | 2 × 5 × 7 |
---
Now fill in the boxes:
- 50: $ 2 \times 5^2 $
- 56: $ 2^3 \times 7 $
- 42: $ 2 \times 3 \times 7 $
- 27: $ 3^3 $
- 66: $ 2 \times 3 \times 11 $
- 43: $ 43 $
- 48: $ 2^4 \times 3 $
- 70: $ 2 \times 5 \times 7 $
---
- Always start with the smallest prime (2).
- If the number is odd, skip 2 and try 3, 5, 7, etc.
- Use divisibility rules:
- Divisible by 2 → ends in even digit
- By 3 → sum of digits divisible by 3
- By 5 → ends in 0 or 5
- Keep dividing until all factors are prime.
- Write the final answer in order from least to greatest, using exponents when possible.
---
✔ All problems solved!
Let me know if you'd like a printable version or visual factor trees!
---
🔷 Understanding Prime Factorization:
- A prime number is a number greater than 1 that has no positive divisors other than 1 and itself.
- Prime factorization means expressing a number as a product of prime numbers.
- We can use a factor tree method: divide the number by the smallest prime until all factors are prime.
---
We’ll go through each number one by one.
---
✔ Example Given (24):
They show:
```
24
/ \
6 4
/ \ / \
3 2 2 2
```
So, the prime factors are:
2 × 2 × 2 × 3 → which is 2³ × 3
✔ Correct.
---
Now let’s do the rest:
---
1. 50
Start dividing by smallest prime:
- 50 ÷ 2 = 25 → 2 is prime
- 25 ÷ 5 = 5 → 5 is prime
- 5 ÷ 5 = 1
So, prime factors: 2 × 5 × 5 → 2 × 5²
✔ Answer: 2 × 5²
---
2. 56
- 56 ÷ 2 = 28
- 28 ÷ 2 = 14
- 14 ÷ 2 = 7 → 7 is prime
So, prime factors: 2 × 2 × 2 × 7 → 2³ × 7
✔ Answer: 2³ × 7
---
3. 42
- 42 ÷ 2 = 21
- 21 ÷ 3 = 7 → 7 is prime
So, prime factors: 2 × 3 × 7
✔ Answer: 2 × 3 × 7
---
4. 27
- 27 ÷ 3 = 9
- 9 ÷ 3 = 3
- 3 ÷ 3 = 1
So, prime factors: 3 × 3 × 3 → 3³
✔ Answer: 3³
---
5. 66
- 66 ÷ 2 = 33
- 33 ÷ 3 = 11 → 11 is prime
So, prime factors: 2 × 3 × 11
✔ Answer: 2 × 3 × 11
---
6. 43
- 43 is a prime number (only divisible by 1 and 43)
✔ Answer: 43 (already prime)
---
7. 48
- 48 ÷ 2 = 24
- 24 ÷ 2 = 12
- 12 ÷ 2 = 6
- 6 ÷ 2 = 3 → 3 is prime
So, prime factors: 2 × 2 × 2 × 2 × 3 → 2⁴ × 3
✔ Answer: 2⁴ × 3
---
8. 70
- 70 ÷ 2 = 35
- 35 ÷ 5 = 7 → 7 is prime
So, prime factors: 2 × 5 × 7
✔ Answer: 2 × 5 × 7
---
9. 48 — already done above
Wait! 48 appears twice? Let's check:
Looking at the image layout:
- Row 1: 50, 56
- Row 2: 42, 27
- Row 3: 66, 43
- Row 4: 48, 70
- Row 5: 48, 70 ← Wait, 48 and 70 again?
But actually, looking at the structure:
It seems like there are two rows of numbers:
- First row: 50, 56
- Second: 42, 27
- Third: 66, 43
- Fourth: 48, 70
- Fifth: 48, 70 → possibly typo or repeat?
But likely, the last two boxes are meant to be separate entries. Let’s assume they are:
- 48 (again) and 70 (again), but maybe it's a mistake.
But since both are already solved, we'll just list them again.
Wait — actually, in the image, the bottom row says:
> 48 70
So only one instance of each.
But earlier we did 48 and 70 already.
So now, let’s double-check all:
---
Final Answers:
| Number | Prime Factorization |
|--------|---------------------|
| 50 | 2 × 5² |
| 56 | 2³ × 7 |
| 42 | 2 × 3 × 7 |
| 27 | 3³ |
| 66 | 2 × 3 × 11 |
| 43 | 43 (prime) |
| 48 | 2⁴ × 3 |
| 70 | 2 × 5 × 7 |
---
✔ Completed Worksheet:
Now fill in the boxes:
- 50: $ 2 \times 5^2 $
- 56: $ 2^3 \times 7 $
- 42: $ 2 \times 3 \times 7 $
- 27: $ 3^3 $
- 66: $ 2 \times 3 \times 11 $
- 43: $ 43 $
- 48: $ 2^4 \times 3 $
- 70: $ 2 \times 5 \times 7 $
---
📌 Tips for Students:
- Always start with the smallest prime (2).
- If the number is odd, skip 2 and try 3, 5, 7, etc.
- Use divisibility rules:
- Divisible by 2 → ends in even digit
- By 3 → sum of digits divisible by 3
- By 5 → ends in 0 or 5
- Keep dividing until all factors are prime.
- Write the final answer in order from least to greatest, using exponents when possible.
---
✔ All problems solved!
Let me know if you'd like a printable version or visual factor trees!
Parent Tip: Review the logic above to help your child master the concept of for math worksheet prime factorization.