Prime Number Hunt
Reminder: 1 is neither prime
nor composite. It is not prime
because it does not have
exactly two factors. It is not
composite because it does not
have more than 2 factors. 1 is
a special number.
Materials: 2 dry erase markers, laminated number grid (1- 50), recording sheet
______________________________________________________________________________
Review: A prime number is a whole number greater than zero that has exactly two different
factors, one and itself. For example, 5 is a prime number because its only two factors are
1 and 5. A composite number is a whole number greater than zero that has more than two
different factors. For example, 8 is a composite number because its factors are 1, 2, 4, and 8.
1. Work with a partner. Collect a number grid (1- 50). Designate
one color marker for the prime numbers and another to cross out
composite numbers.
2. Take turns to cross out a composite number (1 point), circle a
prime number (3 points), or “pass”.
3. Record your answers on the recording sheet.
4. The player with the most points at the end wins!
©K-5MathTeachingResources.com
1
11
21
31
41
2
12
22
32
42
3
13
23
33
43
4
14
24
34
44
5
15
25
35
45
6
16
26
36
46
7
17
27
37
47
8
18
28
38
48
9
19
29
39
49
10
20
30
40
50
©K-5MathTeachingResources.com
Player 1: ____________________________
Number
Factors
Prime or Composite?
Points
Total: _______________
Player 2: ____________________________
Number
Factors
Prime or Composite?
Points
Total: _______________