Foreword N umeracy tests are amongst the most widespread measures that employers apply in selecting staff. I have come across their use for shop-floor factory and retail staff, for com- puter programmers, croupiers, sales people, managers, space scientists and top civil servants. The last group included the head of the Inland Revenue ­ the most senior tax job in the country ­ and it was interesting that even there not all of the highly qualified candidates did well! So, numeracy tests are widely valued by employers to help them make distinctions