These are recommended resources your son or daughter can use to prepare for their GCSE Mathematics:

Monthly calendars

http://www.accessmaths.co.uk/uploads/4/4/2/3/44232537/christmas_revision_calendar_higher.pdf

https://justmaths.co.uk/2017/10/29/a-little-every-day-november-2017/#post/0

https://justmaths.co.uk/2017/09/30/a-little-every-day-october-2017/

5-a-day tasks

https://corbettmaths.com/5-a-day/gcse/

Topic specific

https://vle.mathswatch.co.uk/vle/ (id supplied by your maths teacher)

https://www.mymaths.co.uk/ (id supplied by your maths teacher)

https://corbettmaths.com/

https://hegartymaths.com/

http://www.mathsgenie.co.uk/

http://mrcartermaths.com/

http://mathsbot.com/

http://www.transum.org/Software/Transum_Topics.asp