Finding Factors, GCF, and LCM of Numbers

What is the first step in finding all the factors of a number?

• Start with the number two

• Start with the number one

• Start with the number zero

• Start with the largest number

Tags

CCSS.4.OA.B.4

Why is the number two always a factor of even numbers?

• Because it is a multiple of four

• Because it is a factor of all numbers

• Because even numbers are divisible by two

• Because it is the smallest prime number

Tags

CCSS.5.OA.B.3

How can you quickly determine if three is a factor of a number?

• By checking if the number ends in a zero or five

• By checking if the number is even

• By adding the digits of the number and checking if the sum is divisible by three

• By dividing the number by two

Tags

CCSS.3.OA.D.9

What indicates that you have found all factors of a number when creating a factor list?

• When you find a prime number

• When you reach the number ten

• When you find a factor pair that is a number times itself

• When you find an odd number

Tags

CCSS.4.OA.B.4

What is the greatest common factor (GCF) of 36 and 48?

• 12

• 24

• 8

• 6

Which of the following is NOT a common factor of 36 and 48?

• 5

• 3

• 2

• 1

How do you find the least common multiple (LCM) using the greatest common factor (GCF)?

• Multiply the GCF by the sum of the two numbers

• Multiply the GCF by the two numbers across from it in the factor lists

• Divide the GCF by the two numbers

• Add the GCF to the two numbers

What is the least common multiple (LCM) of 36 and 48?

• 72

• 144

• 192

• 96

In the ladder method, what do you write on the outside of the division sign?

• The product of the two numbers

• The sum of the two numbers

• The largest common factor

• The smallest common factor

How can you verify the least common multiple (LCM) using the ladder method?

• By subtracting the numbers at the bottom

• By adding the numbers at the bottom

• By cross-multiplying the numbers at the bottom with the numbers at the top

• By dividing the numbers at the bottom