Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Worthwhile investment

Enjoying this. Like to work them while listening to the news on TV and such. No pencil to sharpen, no erasing, lots of crosswords in one small package. Also, consider the Solitaire game. These can occupy a person without a need for space or surface to write on. Nice diversions and should continue to get something from them for a long time as they pack so many puzzles or game variations into them.