Can you not just use a search engine (e.g. yahoo) and type numerical reasoning tests ?
The first one I saw was Deloitte's, seems a reasonable port of call if you are looking for numerical reasoning tests.
There are also loads of books with titles like "How to have a CEO's numerical abilities in one easy page", "We know you have a PHD in Maths, but we bet you'd like to pass this" and the lesser known "How to excel at numerical tests with a broken pencil and a bad-tempered secretary who would rather eat it than let you work here".
You might have to trawl the second hand bookshops for that one though, it could be out of print !