Calculate the Greatest Common Factor or GCF of 6, 18, 21 and 30
Sponsors
The instructions to find the GCF of 6, 18, 21 and 30 are the next:
1. Decompose all numbers into prime factors
| 6 | 2 |
| 3 | 3 |
| 1 |
| 18 | 2 |
| 9 | 3 |
| 3 | 3 |
| 1 |
| 21 | 3 |
| 7 | 7 |
| 1 |
| 30 | 2 |
| 15 | 3 |
| 5 | 5 |
| 1 |
2. Write all numbers as the product of its prime factors
| Prime factors of 6 | = | 2 . 3 |
| Prime factors of 18 | = | 2 . 32 |
| Prime factors of 21 | = | 3 . 7 |
| Prime factors of 30 | = | 2 . 3 . 5 |
3. Choose the common prime factors with the lowest exponent
Common prime factors: 3
Common prime factors with the lowest exponent: 31
4. Calculate the Greatest Common Factor or GCF
Remember, to find the GCF of several numbers you must multiply the common prime factors with the lowest exponent.
GCF = 31 = 3
Also calculates the: