How to Find the Greatest Common Factor for 7 and 21

You can find the greatest common factor (GCF) of 7 and 21 by listing the common factors for each number and then identifying the greatest factor in each list. Here's the step-by-step process: Step 1: List the Factors of 7 • The factors of 7 are the numbers that can evenly divide 7. In this case, they are 1 and 7. Step 2: List the Factors of 21 • The factors of 21 are the numbers that can evenly divide 21. In this case, they are 1, 3, 7, and 21. Step 3: Identify the Common Factors • Compare the lists of factors for 7 and 21 to find the common factors. The common factor is the number that appears in both lists. Common Factor: 7 Step 4: Determine the Greatest Common Factor • Finally, the greatest common factor (GCF) of 7 and 21 is 7. So, the GCF of 7 and 21 is 7. Note: In this case, there is only one common factor, which is 7. This is because 7 is the largest number that evenly divides both 7 and 21.