DUDEK Emil: Here is a rather splendid ten digit scientific from 1975. it has the early CASIO baroque style of the period, shared by the older fx-10 and the briefcase models 103-mr & 803-mr with a square-jaw case and square edged buttons. The function set is similar but less complete than the later fx-19, but this model has 10 digits. it also takes 4AA cells. The display is very good with a spare digit for minus and the gap between a ten digit mantissa and the two digit exponent. Conceptually this is a throwback to the fx-10, but the function set is much improved and the calculation speed increased. The right most digit flickers whilst calculating like the fx-20 and the small zero digit has gone and exponents of up to +/-99 are allowed. A switch for degrees or radians has appeared, but no sign yet of gradians or fractions. Llike earlier models a 10^x button is not present, since x^y can be used for this, although conveniently this model has a x^2 button which doesn’t appear again until arc is replaced by an inv button on later models like the fx-39. The calculation algorithms appear very similar to the fx-19 and improved from the fx-20, but interestingly cos stops at 1530, sin & tan at 1440 like the fx-20. later models all stop at 1440 until much later.