In the desktop PC world, every year brings major changes. Before starting any programming project, decide what the program needs to do, who it's for, what's involved in writing it, and what you're going to do with it after you've written it. If you're looking for mathematical exercise, perhaps you can avoid programming. These are powerful and versatile spreadsheets with algebraic formulas and good reporting. Many personal programs, in fact lots of the commercial software we buy, can be replaced by a few formulas in a spreadsheet.
Commercial programs create the data.
If the program is for personal use, it has to solve a problem and be usable, but it doesn't have to look pretty. I' ve written large tools as word processor macros. Commercial-quality programs must look good. While you're writing programs for a portable computer, you probably won't write programs with the portable computer. Most programming tools require heavy hardware with more hard disk space than we could imagine only a few years ago.