Below are some useful maths websites
Arithmetic practice – printable or online SATs style tests
https://mathsbot.com/primary/ks2
Arithmetic practice – compact version that can be completed online
https://mathsbot.com/primary/ks2Mini
Free CGP 3 x ten minute tests for both maths and SPAG with a timer. It tells them what they have got wrong at the end and gives them a score.
Who wants to be a millionaire game for maths
https://www.mathsisfun.com/games/mathionaire-general-math-quiz.html
Maths adventure game
Guardians: Defenders of Mathematica – KS2 Maths game - BBC Bitesize