Qalculate! - Qalculate! is a multiplatform multi-purpose desktop calculator.
PyCharm Community Edition - "The intelligent Python IDE with unique code assistance and analysis, for productive Python development on all levels."
NoteCalc - Browser-based notepad built for math calculations.
Microsoft Office Excel - Microsoft Office Excel is a commercial spreadsheet application.
Soulver - Soulver is a software application that functions as a calculator that allows you type a continuous stream of information rather than having to input data into multiple cells.
Google Sheets - Synchronizing, online-based word processor, part of Google Drive.