Putting Casio fx-991CW in perspective.

[lrdheat]

I do like that it uses 22 or 23 digits internally, produces exact fractions, pi multiples or fractions more often than other machines. When integrating near a discontinuity/vertical asymptote, one can integrate using a lower or upper limit 1*10^-17 or -18 from the vertical asymptote and get a very accurate result. From a statistics point of view, retention of data when changing modes or powering off is very welcome.