Casio FX-570ES Scientific Calculator

The casio fx-570ES is a beautifully made scientific calculator, identical with the fx-991ES, except that this model is powered by a small AAA torch battery, while the 991ES has a solar cell assisted by a small button size LR44 battery, much cheaper than the lithium cells used by Casio in the past.

Both models have 403 functions,including permutations and combinations, bi-variate regression, "solve" and "calc" functions for any equation, 3 simultaneous equations and matrices. In fact they are the most advanced scientific calculators currently in the Casio range, except for the graphic range which are much larger, complicated to operate and therefore slower. The key action is perfect as we have come to expect from Casio and the lettering for the secondary functions is black and brown on brushed aluminium back ground, rather than that aweful yellow, and red lettering on black background use by Casio in the past, which was so difficult to read in artificial light at home.

But perfect though these two models are in what they do, they have one great deficiency which prevents me from giving them an "excellent" rating: they are not programmable. This clearly indicates that they were designed for school and college work, rather than serious scientific or professional work. A great pity.