Using prime numbers

Using prime numbers

Pencil and paper
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
This task is about factorising numbers.
a)  The bold numbers below are sums of 2 prime numbers.
     Write these prime numbers in the circles.
 
i)
 
 ii) iii)
 

iv)
 

v)

vi)
 
 
b)  The bold numbers below are products of 2 prime numbers.
     Write these prime numbers in the circles.
 
i) ii) iii)

 

Task administration: 
This task is completed with pencil and paper only.
Level:
4
Curriculum info: 
Maths, Number and Algebra, Number Knowledge
Keywords: 
prime numbers, factors
Description of task: 
Students find the prime numbers that add or multiply to given sums or products.
Learning Progression Frameworks
This resource can provide evidence of learning associated with
Multiplicative thinking, sets 6-7
within the Mathematics Learning Progressions Frameworks.
Read more about the Learning Progressions Frameworks.
Answers/responses: 
 

Y9 (11/1996)
a)
i)   5, 7
ii)  5, 11 or 3, 13
iii) 5, 19 or 7, 17 or 11, 13
iv) 17, 19 or 13, 23 or 7, 29 or 5, 31
v)  17, 23 or 11, 29 or 3, 37
vi) 19, 29 or 17, 31 or 11, 37 or 41, 7 or 5, 43
moderate
moderate
moderate
moderate
moderate
moderate
b)
i)   3, 13
ii)  5, 11
iii) 7, 13
moderate
difficult
difficult