Notes:

This is a peculiar calculator. It has a special key, the "P"key which function is determined using a slider. This slider has the following positions:
 √  Square roots. The "P"key will
calculate the square root of a gven number.
 GT  Memory calculation. The "P"key will
display the "Grand Total" of all calculations so far. Every time
the "="key is pressed after the last time the
"AC"key was pressed, the result is added to this "Grand
Total". The "Grand Total" memory works independent from the
calculators regular memory.
 rem  Remainder This setting will change the operation
of divisions. Divisions are performed as with integer results, and
the "P"key will show the remainder. Thus, when performing
6 / 4, the result will be 1, and the "P"key will yield 2.
 a^{b}/_{c}  Fractional calculation.
This will change the "P"key into the "fraction" key
present on many CASIO calculators, and will let the calculator
operate on fractions.
 hms  Time calculation. This will change the
"P"key into the "hours minutes seconds" key present on
many CASIO calculators.
 SD  Standard deviation. This will change some keys on
the calculator. The "="key will act as a Σ+
operator. The memory keys will perform the statistical functions
displayed above them. The normal memory functions are unavailable
in this mode. The "P"key will calculate the standard
deviation.
All in all, a very unusual design.
Even though this calculator has some sophisticated scientific
functions it has a quite common bug in that this calculator has no
problems with negative square roots and thinks √9 = 3.
