Group the words "pencil," "eraser," "ruler," "compass," and "calculator" into two categories.
Stationery supplies: Pencil, eraser, ruler, compass 

Mathematical tool: Calculator
Complete the following task based on the instruction and optional input provided.### Instruction:
Group the words "pencil," "eraser," "ruler," "compass," and "calculator" into two categories.

### Output:
Stationery supplies: Pencil, eraser, ruler, compass 

Mathematical tool: Calculator