CRG,
I applied (and passed screening) in 2002 while serving in the Army. I Had not completed y12 at the time. In fact I had only completed y10 with NSW maths in society - one up from general (vegie) maths.
At that time in service applicants for Army pilot need not have completed year 12 to undertake pilot's cse. The rules were changed in about 2003 and so I was placed on the Army y12 Cse to complete the nessesary requirements. This course no longer exists, however, it was basically the QLD OLI TAFE Cert. IV in ATP sylabus, run by the Army's Enoggera RTC. The required maths level is QLD maths B/ NSW 2 Unit.
I don't beleive the course made any difference to my practical application of maths in the cockpit (the physics was more useful) but it is a box they, and some other employers want ticked. I know of pilots with ATPL (A) and (H) licences, Uni degrees and who were already reservists who were knocked back for pilot due to lack of year 12 maths.
If you want contact details for the TAFE maths course (can be completed by correspondence) feel free to PM me.