Hi Mixmaster
Found these quite useful practice stuff:
http://www.kent.ac.uk/careers/tests/mathstest.htm
http://www.excitingfutures.com/numericalreasoning.htm
http://www.assessmentday.co.uk/Pract..._numerical.htm
Some are for use with a calculator but can be done easily enough with pencil and paper, just forget the time limits they suggest.
Enjoy