5.3 Study Guide
Prime/Composite & Odd/Even
Learning Goals
5.3
a) identify and describe the characteristics of prime and composite numbers; and
b) identify and describe the characteristics of even and odd numbers.
Vocabulary
Divisible - capable of being divided by another number without a remainder
Even - any number ending in 0, 2, 4, 6, or 8
Odd - any number ending in 1, 3, 5, 7, or 9
Natural Number - the counting numbers
Prime Number - a natural number with exactly two factors (itself and one)
Composite Number - any natural number with more than two factors
Product – the answer in multiplication
Factor - a number that is multiplied by another number to find a product.
Example: factor x factor = product
Multiple - the product of that number and any other whole number
Example: the multiples of 3 are 3,6, 9, 12…
Practice at Home

Practice identifying prime and composite numbers (to 100) by using the following steps to
determine if a number is prime or composite:
Prime
#
2
3
Composite Numbers
Multiples of 2
Multiples of 3
Divisibility Rule
Even numbers > 2
If the sum of the digits of a
number is divisible by 3, then
the number is divisible by 3.
Example: 78 - 7+8=15 (a multiple of
3) so 78 is divisible by 3.
5
7
Multiples of 5
Multiples of 7
Numbers ending in 0 and 5
This rule is quite complicated.
Students can use calculator to
determine if it is divisible by 7.
** The number 1 is neither prime nor composite.

To determine if a number is odd or even, look at the ONES place.
786 is EVEN because there is a 6 in the ones place.
483 is ODD because there is a 3 in the ones place
Sample Questions
1.
Which is a prime number?
A
B
C
D
2.
Which is a composite number?
A
B
C
D
3.
1
2
3
4
Which number is even?
A
B
C
D
7.
45
67
86
91
Which number is neither prime nor composite?
A
B
C
D
6.
31
49
79
97
Which number is not composite?
A
B
C
D
5.
7
9
17
19
Which number is not prime?
A
B
C
D
4.
2
4
18
27
27
34
41
63
Which number is odd?
A
B
C
D
36
43
50
78