To improve problem solving skills and apply everything learnt in class the UK Mathematical Trust runs a maths challenge every year. This is a link to previous test papers with answers which will provide a challenge:

http://www.ukmt-resources.org.uk/index-tr.html

 

The nrich project aims to enrich the mathematical experience of all learners. Their website has amazing problems and games for all levels:

http://nrich.maths.org/frontpage