VLOOKUP vs XLOOKUP in Excel
The approximate-match default is the most expensive mistake in spreadsheets, because it returns a plausible wrong number rather…
Articles & Guides
Plain-English explanations of unit conversions, everyday maths, health metrics and personal finance — each with the formula, worked examples and a matching calculator.
Windows Keyboard Shortcuts Worth Learning
Six shortcuts learned properly beat a printed list of two hundred. Starting with clipboard history, which is off by default and…
How to Compress a PDF
One test tells you whether this takes thirty seconds or needs image work: try to select the text.
HTML for Beginners
HTML describes what content is, not what it looks like. Getting that split right is most of what separates working markup from…
How to Center a Div in CSS
The modern answer is two lines. What makes centring feel hard is that every failure mode is silent — starting with a parent that…
Git and GitHub for Beginners
Git makes sense once you hold the three-places model. Includes the undo table and the reflog recovery most tutorials leave out.
How to Take a Screenshot on Windows
Five shortcuts, and the column that actually matters: which ones save a file and which only touch the clipboard.
How to Take Better Notes
The test of a note-taking system is not how the notes look, but whether writing them made you think — and whether you can test…
How to Write Better AI Prompts
Techniques that reliably change output quality, and an honest list of the widely shared advice that is cargo cult.