https://precomputing.com/tags/explainer/ Recent content in Explainer on precomputing.com Hugo en-us Tue, 29 Sep 2026 00:00:00 +0000 https://precomputing.com/precomputing-explained-keep-a-running-total-instead-of-counting-again/ Tue, 29 Sep 2026 00:00:00 +0000 https://precomputing.com/precomputing-explained-keep-a-running-total-instead-of-counting-again/ <p>A lot of software that collects data works like a shop owner with a shoebox. Every receipt goes in the box. When someone asks how much the shop sold today, she tips the box out and adds everything up, and if they ask again an hour later she does it all over again, with a bigger pile.</p> <p>Precomputing works like a notepad next to the till. Each sale is added to a running total the moment it happens, so a question gets answered by reading one number. Now and then the box can be emptied. She keeps only the odd receipts (a huge refund, a sale at 3 a.m.) in case someone asks about them later.</p>