Math Lesson 49 Least Common Multiple
30 is a multiple of 6. True or False
True
Dante is planting his rose garden. He knows he can plant all of his roses by planting 12 or 15 rose bushes in a row. What is the least number of rose bushes Dante could have? a. 60 rose bushes b. 30 rose bushes c. 45 rose bushes d. 24 rose bushes
a. 60 rose bushes
Find the LCM 12 and 9 a. 3 b. 36 c. 12 d. 216
b. 36
The LCM of two square numbers is another square number. Is this statement sometimes, always, or never true? Explain your answer.
Always because the numbers are square and when you find the LCM you get a square number like the numbers 25 and 36 the LCM is 900 and 30 x 30 is 900.
27 is a multiple of 4. True or False
False
b. Figure B
Which of the following fraction models represents the difference 4/5 - 2/3? a. Figure A b. Figure B c. Figure C d. Figure D
Find the LCM 20, 2 and 6 a. 2 b. 6 c. 60 d. 20
c. 60
Find the sum: 1/3 + 1/4 a. 1/12 b. 2/7 c. 7/12 d. 1
c. 7/12
Find the difference: 4/5 - 1/3. a. 3/2 b. 3/15 c. 7/15 d. 17/15
c. 7/15
One way to find the LCM: Making a List
Making a list. 1) List the nonzero multiples of each number. 2) Identify the LCM from the common multiples.
35 is a multiple of 3. True or False
False
Ana. Ana found the LCM and Kurt found the GCF.
Kurt and Ana are finding the LCM of 6 and 8. Who is correct?
common multiples
Multiples that are shared by two or more numbers. For example, some common multiples of 2 and 3 are 6, 12, and 18. *Multiples of 2: 0,2,4,6,8,10,12,14,16,18.... Multiples of 3: 0,3,6,9,12,15,18,21,24... Common Multiples are 6, 12, and 18.
multiple
The product of any number and a whole number is a multiple of that number. *Multiples of 3: 0,3,6,9,12,15,18,21,24... Multiples of 4: 0,4,8,12,16,20,24,28... The LCM of 3 and 4 is 12.
least common multiple
The smallest number, other than zero, that is a multiple of two or more given numbers. The LCM of 2 and 3 is 6. *Multiples of 3: 0,3,6,9,12,15,18,21,24... Multiples of 4: 0,4,8,12,16,20,24,28... The LCM of 3 and 4 is 12.
Another way to find the LCM: Using prime factors
Using Prime Factors. 1) Write the prime factorization for each number. 2) Identify all common primes. 3) Multiply each common prime factor once and any remaining factors.Find the LCM of 15 and 25 by using prime factors.
d. Asia
Which continent makes up the most of Earth's land? a. Europe b. North America c. Antarctica d. Asia
Find the LCM 20, 2, and 25 a. 100 b. 20 c. 2 d. 50
a. 100
Find the LCM 2, 11, and 9 a. 198 b. 99 c. 1 d. 22
a. 198
Find the LCM 20 and 4 a. 20 b. 5 c. 160 d. 4
a. 20
Which of the following is the lowest common denominator for the fractions 5/6 and 3/4? a. 4 b. 12 c. 15 d. 24
b. 12
The high school marching band rehearses with either 6 or 10 members in every line. What is the least number of people that can be in the marching band? a. 20 people b. 30 people c. 36 people d. 60 people
b. 30 people
Find the LCM 6 and 3 a. 36 b. 6 c. 2 d. 3
b. 6
Write as a mixed number in simplest form. 38/5 a. 8 3/5 b. 7 3/5 c. 6 3/5 d. 6 4/5
b. 7 3/5
Write as a mixed number in simplest form. 27/6 a. 5 1/2 b. 3 5/6 c. 4 1/2 d. 3 1/2
c. 4 1/2
Omar is planting trees. he has enough trees to plant 6,7, or 14 trees in a row. What is the least number of trees Omar could have? a. 21 b. 14 c. 42 d. 84
c. 42
Find the LCM 15,10, and 25 a. 30 b. 50 c. 5 d. 150
d. 150
Find the LCM 15 and 20 a. 15 b. 480 c. 4 d. 60
d. 60
Find the LCM of 5 and 8
multiples of 5: 5,10,15,20,25,30,35,40 multiples of 8: 8, 16, 24, 32, 40, 48 LCM: 40
Find the LCM of 9 and 12 by making a list.
multiples of 9: 9,18,27,36,45,54, multiples of 12: 12, 24, 36, 48, 60 36 is the LCM
