r is the correlation coefficient in statistics mode. The way to compute it is different for each statistics submode, the calculator implements this with a lookup table to find out the function to call. If the submode is unexpected, the array is accessed out-of-bound and the code jumps to an unintended section.

Currently there are 2 methods to type r in an unintended mode, without invoking basic overflow.

ES PLUS series

fx-570ES PLUS / fx-991ES PLUS

Enter mode 68

Source: http://tieba.baidu.com/p/1735724120

  • Use this method to get r in COMP mode.
  • Modify the formula to get
(1)
\begin{align} \sqrt{\int_1^1{X^2 \text{dx}} \sqrt3 r} \end{align}
  • Press [=].

Misc 1

  • Use this method to get r in COMP mode.
  • Modify the formula to get ((((((1(1)r.
  • Press [M+].