Vocabulary Definitions
What do we call a number with exactly two factors: 1 and itself?
Prime
Give an example of a prime number less than 20.
7 (or 2, 3, 5, 11, 13, 17, 19)
What does LCM stand for?
Least Common Multiple
What does it mean if a number is divisible by another?
It divides evenly with no remainder
Use the word 'prime' in a math sentence.
Example: 7 is a prime number because it has only two factors.
What do we call a number with more than two factors?
Composite
Give an example of a composite number less than 20.
12 (or 4, 6, 8, 9, 10, 14, 15, 16, 18)
What does GCF stand for?
Greatest Common Factor
A number is divisible by 2 if it is ______.
Even
Use the word 'factor' in a math sentence.
Example: 5 is a factor of 20.
Define a factor.
A number that divides another exactly
List all the factors of 18.
1, 2, 3, 6, 9, 18
What is the LCM of 6 and 8?
24
A number is divisible by 5 if it ends in ______.
0 or 5
Use the word 'multiple' in a math sentence.
12 is a multiple of 6.
Define a multiple.
The product of a number and an integer
Name three multiples of 7 greater than 20.
21, 28, 35 (etc.)
What is the GCF of 24 and 36?
12
A number is divisible by 10 if it ends in ______.
0
Use the word 'divisible' in a math sentence.
24 is divisible by 3.
What is the difference between a factor and a multiple?
A factor divides a number, a multiple is a product of a number
A teacher has 36 markers and 48 pencils. What is the greatest number of identical sets she can make?
12 sets (GCF of 36 and 48 = 12)
Explain in your own words: when would you use LCM vs GCF?
LCM when events repeat (schedules); GCF when dividing items evenly
Write your own divisibility rule for any number and give an example.
Student examples vary (e.g., divisible by 4 if last two digits divisible by 4)
Create a short word problem that uses both LCM and GCF.
Example: Two bells ring every 6 and 8 minutes. When will they ring together? (LCM). If 36 and 48 students are grouped equally, what’s the largest group size? (GCF).