# Prime Numbers Reasoning and Problem Solving

```Prime Numbers
Prime Numbers
1a. Choose from the digit cards below to
create composite numbers up to 100.
6
2
9
1b. Choose from the digit cards below to
create composite numbers up to 100.
7
3
Find all the possibilities.
PS
2a. Place the numbers below on the Venn
diagram.
Prime numbers
53
Multiples of 2
27
7
1
8
Find all the possibilities.
D
18
4
2
28
D
2b. Place the numbers below on the Venn
diagram.
Composite
numbers
47
D
PS
73
PS
3a. True or false?
62
Multiples of 3
19
69
56
40
39
D
PS
3b. True or false?
The largest prime number
less than thirty is 29.
All odd numbers are prime
numbers.
Jacob
Luna
D
R
&copy; Classroom Secrets Limited 2018
D
classroomsecrets.co.uk
Reasoning and Problem Solving – Prime Numbers – Year 5 Developing
R
Prime Numbers
Prime Numbers
4a. Choose from the digit cards below to
create composite numbers up to 50 that
have a prime factor of 2.
4
6
3
4b. Choose from the digit cards below to
create composite numbers up to 50 that
have a prime factor of 3.
1
8
Find all the possibilities.
1
2
7
Find all the possibilities.
E
PS
E
PS
5a. Place the numbers below on the Venn
diagram.
5b. Place the numbers below on the Venn
diagram.
Prime factors
of 20
Prime factors
of 66
20
2
Prime factors
of 30
15
5
3
30
10
E
33
PS
6a. True or false?
22
2
31
3
PS
6b. True or false?
2 is the only even prime
number.
Alfie
Grace
&copy; Classroom Secrets Limited 2018
11
E
Every odd composite
number has 3 as a prime
factor.
E
7
Prime factors
of 63
R
E
classroomsecrets.co.uk
Reasoning and Problem Solving – Prime Numbers – Year 5 Expected
R
Prime Numbers
Prime Numbers
7a. Choose from the digit cards below to
create composite numbers up to 50 that
have a 2-digit prime factor.
6
1
3
7b. Choose from the digit cards below to
create composite numbers up to 50 that
have only two prime factors.
4
5
Find all the possibilities.
2
3
1
Find all the possibilities.
GD
PS
GD
PS
8a. Place the numbers below on the Venn
diagram.
8b. Place the numbers below on the Venn
diagram.
Sum of prime
factors &gt; 15
Sum of prime
factors &lt; 20
39
26
Has 2 as a
prime factor
46
33
38
49
34
GD
26
PS
9a. True or false?
15
Has 5 as a
prime factor
38
35
85
55
14
GD
PS
9b. True or false?
All 2-digit composite
numbers have a prime
factor of 2.
The sum of the prime factors
of any composite number is
always odd.
Judy
Theo