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Grade 4 · Worksheet

Numbers and sequences

Prime & composite numbers

Name: ______________________________Date: ______________Score: ______ / 20

1.
Which of these is a prime number?
1. A11
2. B21
3. C51
4. D9
2.
Which of these is a prime number?
1. A31
2. B39
3. C49
4. D21
3.
How many factors does a prime number have?
4.
A number with more than two factors is called a…
1. Acomposite number
2. Bprime number
3. Csquare number
4. Dfactor
5.
Which of these numbers is NOT prime?
1. A9
2. B2
3. C3
4. D7
6.
Which of these is a composite number?
1. A15
2. B13
3. C17
4. D19
7.
What is the smallest prime number?
8.
Which list contains only prime numbers?
1. A2, 3, 5, 7
2. B1, 2, 3, 4
3. C2, 4, 6, 8
4. D9, 15, 21
9.
7 is a prime number.
True False
10.
21 is a prime number.
True False
11.
67 is a prime number.
True False
12.
64 is a prime number.
True False
13.
51 is a prime number.
True False
14.
98 is a prime number.
True False
15.
90 is a prime number.
True False
16.
77 is a prime number.
True False
17.
73 is a prime number.
True False
18.
89 is a prime number.
True False
19.
79 is a prime number.
True False
20.
78 is a prime number.
True False

Answer key

Numbers and sequences — Prime & composite numbers

1.A. 11
2.A. 31
3.2
4.A. composite number
5.A. 9
6.A. 15
7.2
8.A. 2, 3, 5, 7
9.True
10.False
11.True
12.False
13.False
14.False
15.False
16.False
17.True
18.True
19.True
20.False