Prime Numbers
Solve problems by finding the prime factors of numbers.
Number Framework Stage 8
Using Materials
Problem: “Gerry builds rectangles out of 6 square tiles. Find all the ways of building rectangles with these tiles.”
(Answer: 
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“Repeat for 7 tiles.”
(Answer: 
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Discuss why 7 is called a prime number and 6 is not.
(Answer: There is only one way of building 7 namely 7 tiles in a single row. Whereas 6 can also be built as 2 rows of 3.)
Examples: By building rectangles out of tiles determine which of these numbers are prime and which are not: 5 8 11 9 15 13 16.
Understanding Number Properties:
Explain why 2 is the only even prime number.
Using Number Properties
Problem: “7 has factors 1 and 7, and 7 is a prime number. 6 has factors 1, 2, 3, and 6, and 6 is not a prime number. Complete this general rule: If we look at all the factors of a number, we know when it is a prime number if..".
Similar Resources
Systematic Prime Factorisation
Solve problems by finding the prime factors of numbers.
Factor Trees
Solve problems by finding the prime factors of numbers.
The Sieve of Eratosthenes
Solve problems by finding the prime factors of numbers.
Recurring and Terminating Decimal Fractions
Solve problems by finding the prime factors of numbers.
Prime Time
This is a level 5 number activity from the Figure It Out series. It relates to Stage 8 of the Number Framework.
