CASIO fx-991CW

[jonmoore]

The unfortunate truth regarding Casio calculators such as the 991 series is that bad design decisions in large part happen because of pressures from eduction institutions. You witness this in significant differences is functionality that's available across the regions of the world.

As a prime example, in the last generation of calculators, this effected the UK with GCD and LCM being removed, whilst it was included across most of continental Europe and Australasia (not totally certain regarding the US market, but I believe it was the same as the UK).

I strongly agree with the central tenet of pre-university mathematics education that symbolic manipulation is a problem-solving skill that can only be learnt through lots of practice, but to include mechanistic calculation functions such as GCD and LCM within this tenet is wrong as it proves nothing regarding the mathematical abilities of the student. But the UK teaching pressure groups were pedantically opposed to such functions, so they had to go.

As a design strategist, I hated the industrial design of the 991EX which tried far to hard to appeal to the fashionable young student with a faux carbon fibre fascia that obscured the labelling on said fascia (particularly under artificial light). I believe this was one of the primary reasons for the simplification of the design of the current generation of 991 calculators. One of the clichés of design is that rounded design elements are more 'friendly'. I can almost hear the equivalent of me saying this when pitching the design to Casio executives. The biggest irony here is that Casio already had a great design for the previous generation of the 991, and that was the second generation Casio fx-100AU PLUS, the equivalent model for the Australasia market (apologies for the giant image below, I lazily linked to an online image without first resizing it, but on balance at least everything is legible).

The eagled eyed among you will spy the GCD and LCM functions, missing from the UK 991EX. I ended up purchasing the Australasia model for my pre-university aged kids here in the UK as the school allowed them for tests and exams (the mathematics department agreed with my view - I sit on a PTA group responsible for science and mathematics teaching in the school and there was not a single objection when I raised the subject for discussion).

I could go on, but the key discussion point I wanted to describe is that young students (and professionals) are affected by the arbitrary viewpoints of regional education pressure groups. Plus I agree with the majority of views put forward by other reviewers, including those of Eddie and Dave. However, regarding performance, most UK students are recommended to supplement their 991-ex with the graphical Casio Model, the fx-CG-50, which is very fast and approved for those UK exam papers which allow calculators. Unfortunately, it's far from featherlight and pig ugly to boot! It's also a model where many of the key functions are hidden behind menus. In it's favour it has an exam mode which disables functions, programs and any text notes on the device. This is critical as e.g. the CAS from the HP Prime can be installed without any "hacks".