Expressing a number as a product of primes means writing it uniquely as a product of its factors that are prime numbers.

Prime factors are the factors of a number that are, themselves, prime.

Prime factorisation is a method to find the prime factors of a given integer.

Checking and securing understanding of prime factorisation

Maths

In this unit, pupils formalised their understanding of the index laws. This understanding will allow them to perform calculations with values written in standard form more efficiently.

The conditions for standard form mean that pupils have explored how different powers of 10 can be written in the prior unit. In this unit, this understanding is generalised and the index laws formalised.

Arithmetic procedures: index laws

What number is written as $$2 × 5^2 × 19$$ as a product of its prime factors? 

What number is written as $$2 × 5 × 31$$ as a product of its prime factors? 

What number is written as $$3 × 5 × 11$$ as a product of its prime factors? 

Which of these is a prime factor of 10905? 

Which of these is the prime factorisation of 450? 

Which of these is the prime factorisation of 539? 

Calculate 0.25 × 0.94, giving your answer as a decimal.

Calculate 3.25 × 7.94, giving your answer as a decimal.

Calculate -0.3 + 9.1, giving your answer as a decimal.

Calculate 0.28 ÷ 0.04, giving your answer as a decimal.

This lesson will soon be taken down.

Checking and securing understanding of prime factorisation

Lesson outcome