Least Common Multiple
List the first five multiples of 12.
12, 24, 36, 48, 60, ...
List the first five multiples of 18
18, 36, 54, 72, 90, ...
List all the factors of 80.
1, 2, 4, 5, 8, 10, 16, 20, 40 and 80.
List the factors of 32
1, 2, 4, 8, 16, 32
I am a number. If you multiply me by any other number, you always get the same answer. What number am I?
0 or Zero
Given the following multiples, what is the Least Common Multiple of 7 and 3?
multiples of 7: 7, 14, 21, 28, 35, 42, ...
multiples of 3: 3, 6, 9, 12, 15, 18, 21, ...
LCM of 7 and 3 is is 21
What is the least common multiple of 5 and 10?
multiples of 5: 5, 10, 15, 20, 25, ...
multiples of 10: 10, 20, 30, 40, ...
The least common multiple is 10
What is the greatest common factor of 75 and 12?
factors of 75: 1, 75, 3, 25, 5, 15
factors of 12: 1, 12, 2, 6, 3, 4
What is the greatest common factor of 5 and 10? (show all your work to justify your answer!)
gcf is 5
What weighs more, a pound of feathers or a pound of bricks?
They both weigh a pound, so they both weigh the same!
Find the LCM (7, 4)
1. List out the first five multiples of 7 and 4.
2. Circle the multiples that are the same in both lists.
3. Write down the LEAST common multiple
The least common multiple (LCM) of 7 and 4 is 28
Find the LCM of 12 and 10
1. List out the first six multiples of 12 and 10.
2. Circle the multiples that are the same in both lists.
3. Write down the least common multiple
The LCM of 12 and 10 is 60
What is the greatest common factor of 21 and 9? Justify your answer by explaining or showing your work.
GCF of 21 and 9 is 3.
What is the greatest common factor of 36 and 50?
Greatest common factor is 2.
I am an odd number. Take away one letter and I become even. What number am I?
Seven
Find the LCM (15,9)
Show all the steps you did to justify your answer.
LCM (15,9) = 45
Find the LCM (7,6)
Show all the steps you did to justify your answer.
LCM(7,6) = 42
What is the GCF of 210 and 12? Justify your answer by explaining or showing your work.
GCF is 6
What is the GCF of 28 and 40? Justify your answer by explaining or showing your work.
GCF is 4
Mr. Smith has 6 daughters. Each daughter has a brother. How many children does Mr. Smith have total?
Find the LCM of 7, 21, and 35
105
Find the LCM of 32 and 28.
Show all your work to justify your answers.
LCM is 224
The GCF of 45, 10, and _____ is 5. The missing number is not 5.
What is the missing number? Show your work or explain you know your answer is correct.
(There are many possible answers, write your answer and explain / show your work to justify it!)
The GCF of 27, 9, and _____ is 3. The missing number is not equal to 3.
What is the missing number? Show your work or explain you know your answer is correct.
(There are many possible answers, write your answer and explain / show your work to justify it!)
There is a lily pad on a small pond. Each day, the lily pad doubles its size. On day 20 it covers the whole pond. On what day was the lily pad the size of half the pond?
Day 19