The QSlide function displays the calculator panel in a moveable window in the foreground while allowing you to access other phone features in the background.
Touch and hold the Calculator QSlide title bar to move it.
Drag the bottom right corner of the QSlide window to resize it.
Tap the QSlide icon at the upper-left corner of the title bar) to return to the Calculator app.
Drag the circle on the transparency bar to the left to make the QSlide calculator window transparent allowing you to access the screen functions underneath it. Drag it back to the right to use the QSlide window again.
Tap the Close icon (at the upper-right corner of the title bar) to close the Calculator QSlide window.