GCF and LCM

Front

What is the LCM (Least Common Multiple)?

Back

The LCM of two or more numbers is the smallest multiple that is exactly divisible by each of the numbers.

Front

How do you find the LCM of 2, 4, and 6?

Back

List the multiples of each number: 2: 2, 4, 6, 8, 10, 12; 4: 4, 8, 12; 6: 6, 12. The smallest common multiple is 12.

Front

What is the GCF (Greatest Common Factor)?

Back

The GCF of two or more numbers is the largest number that divides each of the numbers without leaving a remainder.

Front

How do you find the GCF of 50 and 100?

Back

List the factors of each number: Factors of 50: 1, 2, 5, 10, 25, 50; Factors of 100: 1, 2, 4, 5, 10, 20, 25, 50, 100. The largest common factor is 50.

Front

What is the relationship between GCF and LCM?

Back

The product of the GCF and LCM of two numbers is equal to the product of the numbers themselves.

Front

How can you use prime factorization to find the LCM?

Back

Factor each number into primes, then take the highest power of each prime factor and multiply them together.

Front

How can you use prime factorization to find the GCF?

Back

Factor each number into primes, then take the lowest power of each common prime factor and multiply them together.

Front

If two neon signs blink every 9 seconds and 15 seconds, how do you find when they blink together?

Back

Find the LCM of 9 and 15, which is 45 seconds.

Front

What is an example of finding the LCM using the listing method?

Back

To find the LCM of 3 and 5, list the multiples: 3: 3, 6, 9, 12, 15; 5: 5, 10, 15. The LCM is 15.

Front

What is an example of finding the GCF using the listing method?

Back

To find the GCF of 12 and 18, list the factors: 12: 1, 2, 3, 4, 6, 12; 18: 1, 2, 3, 6, 9, 18. The GCF is 6.