imaginary unit (i) position on key

[Carlos295pz]

Begins its publication stating that it may not be something important but ends up affirming a poor allocation of keys ... (the interface design is important but this is solved by the manufacturer under factors of use and efficiency). It certainly depends on the user, but the proposed distribution does not sound practical, I do not see the simplicity of typing, rather a grouping by similars that omites efficient typing.

I think currently it has a perfectly friendly distribution, its separation into 2 simple groups, navigation (black zone) and common insertion, continues with the general design of being a simple calculator and not one for expert astronauts.