Carol Vorderman has made her maths website free for the duration of school closures. All teaching is in line with the Mathematics National Curriculum.
Topmarks is a fabulous website for all primary aged children. Just click on your chosen age range to find activities tailored to the National Curriculum for Maths and English. There are opportunities to practise times tables, tell the time, practise spellings and read books to name but a few. There is also a Parents' Resources section offering helpful tips and ideas for keeping children entertained whilst at home.
All KS2 children have home access to Times Tables Rock Stars and for the duration of school closures are allowing access to even more cool maths.