Understanding Lowest Common Multiple

The video tutorial explains how to find the lowest common multiple (LCM) of 12 and 15 using a factor tree. It begins by breaking down the numbers into their prime factors and organizing them in a chart. The rule for finding the LCM is to bring down each number, multiply them together, and calculate the result. The tutorial concludes by demonstrating that this method works for any set of numbers.

What is the first step in finding the lowest common multiple of two numbers?

• Create a factor tree

• Add the numbers together

• Subtract the smaller number from the larger

• Divide the numbers by each other

Tags

CCSS.4.OA.B.4

When organizing prime factors, what should you do if a prime number appears in both numbers?

• Ignore it

• Use it only once

• Multiply it by itself

• Add it to the other number

Tags

CCSS.4.OA.B.4

Which of the following is a prime factor of 15?

• 2

• 4

• 3

• 6

How do you determine the lowest common multiple after organizing the prime factors?

• Subtract the smallest prime factor from the largest

• Multiply the highest power of each prime factor

• Add all the prime factors together

• Divide the sum of the prime factors by two

What is the lowest common multiple of 12 and 15?

• 30

• 45

• 60

• 75