The biggest downside to the fx-991ES PLUS is that To keep your repacked codes "installed" during a break: Don't press [ON]. Let the calculator auto-power off.
Enter the formula above using the Alpha keys and the colon ( : ) from the Integral key. Press CALC .
"Coding" on your Casio is completely safe. These aren't "hacks" that modify the firmware; they are simply creative ways to use the math functions already built into the device. It won't void your warranty or break the calculator. Conclusion
This is the most "repacked" game because it utilizes the calculator's memory to store a hidden value.