How do I… · Excel
A pivot table summarises a list — totals by category, counts by month — without writing a formula. It takes about thirty seconds once the data is shaped right.
If a number column is being counted instead of summed, there is text somewhere in it — often a stray "n/a". Refreshing after the source data changes is manual: right-click the table → Refresh. Turning the source into a Table first (Insert → Table) means new rows are picked up automatically.
This page is written by the people who make Open Portal: press Ctrl+Shift+O, box any part of your screen, and ask about it. Excel included — it works in every app, because it reads pixels rather than plugging into anything.
Faster than searching: box the part of your screen you cannot work out and ask about it directly — in Excel or anywhere else. Answers arrive where you drew the box.