Interesting to see that the highest mandatory qualifications required are 'O' levels in maths and English!
If you took a look at 1960 O level Maths and English papers you might not be so surprised. Certainly O level maths would equip you with most of the mathematical skills required as a pilot or navigator, although I am sure those very few who got into test flying would need something more advanced.
I remember at nav school I regularly scored highest on our course in the frequent mental arithmetic tests and used to pull the leg of one on our course who was a maths graduate about this (I passed O level maths in 1964). He pointed out that that there was more to maths than arithmetic, but I used to say that mental arithmetic was a much more valuable skill to a nav than the ability to understand differential calculus.
Heres another one from the period. I know him well and his lack of A levels or a maths degree certainly didnt hold him back! Terrific pilot - good enough to be entrusted with the BBMF Lancaster for a tour!
http://www.vforcereunion.co.uk/image...rew-1963-4.jpg