algebra –

https://byjus.com/maths/basics-of-algebra/

https://mathsframe.co.uk/en/resources/category/382/Y6-Algebra

https://www.bbc.co.uk/bitesize/guides/z8y9jty/revision/2

https://teachers.thenational.academy/subjects/maths/key-stages/key-stage-3

https://www.thenational.academy/