From an external numeric keypad I expect it the double-assigned keys can be used regardless of the right on the laptop keyboard extends the laptop keyboard to a numeric keypad and. That's when this keypad is not the case: Is it set to numeric input ("NUM"), the keys are placed on the laptop to "NUM". If you use the laptop keys "Pos1", "end", "Ins", "Del" and for "Page Up" and Page Down ", then you can not enter more digits on the numeric keypad. From another number block I'm used to that this can be exploited regardless of the laptop keyboard, thus providing a genuine extension of the keyboard, as is the case with a "big" desktop PC keyboard.
