Understanding GCF and LCM

This video tutorial from Mumo Math and Science explains how to solve word problems involving the greatest common factor (GCF) and lowest common multiple (LCM). It introduces the concepts, provides key terms to identify whether a problem requires finding the GCF or LCM, and demonstrates solving two example problems: one involving hot dogs and buns, and another with sports balls. The video emphasizes using context clues to determine the correct approach and provides step-by-step solutions to each problem.

What is the Greatest Common Factor (GCF)?

• The difference between two numbers.

• The sum of two numbers.

• The smallest number that two or more numbers divide into.

• The largest number that divides two or more numbers.

Which of the following is a keyword indicating a problem might require finding the LCM?

• Greatest

• Most

• Largest

• First

In the hot dogs and buns example, what is the LCM of 10 and 8?

• 20

• 30

• 50

• 40

How many packs of hot dogs should Drew buy if each pack contains 10 hot dogs?

• 4

• 3

• 6

• 5

What is the GCF of 16, 24, and 40 in the sports balls example?

• 8

• 4

• 10

• 6

How many groups of footballs can be made if there are 16 footballs and the GCF is 8?

• 3

• 4

• 2

• 1

In the sports balls example, how many baseballs will be in each group if the GCF is 8?

• 4

• 5

• 3

• 2

Which context clue would suggest finding the GCF?

• Fewest

• First

• Maximum

• Minimum

What is the first step in solving a GCF or LCM word problem?

• Divide the numbers by each other.

• Calculate the sum of the numbers.

• Look for context clues in the wording.

• Multiply the numbers together.

What is the purpose of using context clues in GCF and LCM problems?

• To identify the numbers involved.

• To determine the operation to use.

• To check the final answer.

• To decide whether to find GCF or LCM.