About LCM:

When we multiply a number by each non-zero whole number, we obtain a list known as the multiples of that number. When we do this for several numbers, we can compare those lists to look for a common multiple that has the lowest value. This is known as the least common multiple or LCM.


Test Objectives
  • Demonstrate the ability to generate the multiples of a number
  • Demonstrate the ability to find the LCM using the listing method
  • Demonstrate the ability to find the LCM using the prime factorization of each number
LCM Practice Test:

#1:

Instructions: Find the LCM by listing the multiples of each number.

a) LCM(4, 10)

b) LCM(6, 21)


#2:

Instructions: Find the LCM.

a) LCM(15, 18)

b) LCM(14, 63)


#3:

Instructions: Find the LCM.

a) LCM(24, 81, 156)


#4:

Instructions: Find the LCM.

a) LCM(121, 165, 231)


#5:

Instructions: Find the LCM.

a) LCM(550, 150, 225)


Written Solutions:

#1:

Solutions:

a) LCM(4, 10) = 20

b) LCM(6, 21) = 42


#2:

Solutions:

a) LCM(15, 18) = 90

b) LCM(14, 63) = 126


#3:

Solutions:

Solution:

a) LCM(24, 81, 156) = 8424


#4:

Solutions:

a) LCM(121, 165, 231) = 12,705


#5:

Solutions:

a) LCM(550, 150, 225) = 4950