Here are a couple of links to websites that may be useful for maths and spelling activities a home:
'Maths is fun' offers good step by step instruction on all the numeracy topics, as well as practice questions and examples.
The children in KS2 have a sumdog account which is accessable at home.
This spelling based website offers advice and activities to help with spelling.
BBC Bitesize also offer a good selection of resources that help in a number of curriculum areas.
Primary Homework Help is an excellent site that offers child friendly support on numerous topics.