lcm of 3 and 7
Understand the Problem
The question is asking for the least common multiple (LCM) of the numbers 3 and 7. To solve this, we will identify the multiples of each number and find the smallest multiple that they share.
Answer
21
Answer for screen readers
The least common multiple (LCM) of 3 and 7 is 21.
Steps to Solve
- List the multiples of each number
We list the first few multiples of 3 and 7:
Multiples of 3: 3, 6, 9, 12, 15, 18, 21, ... Multiples of 7: 7, 14, 21, 28, 35, 42, ...
- Find the smallest common multiple
Identify the smallest number that appears in both lists of multiples:
The smallest common multiple of 3 and 7 is 21.
The least common multiple (LCM) of 3 and 7 is 21.
More Information
The LCM is the smallest number that is a multiple of both 3 and 7. Since 3 and 7 are both prime numbers, their LCM must be their product.
Tips
A common mistake is to miss the smallest common multiple by stopping the list too early. Make sure to list enough multiples to find the LCM.
