Case study
Windows Calculator: reconstructing percentage rules
REA’s case traces the installed Windows Calculator model DLL to explain different percentage behavior for multiplication/division and other operations. An analyst-selected function is interpreted against public Microsoft source and demonstrated with fixed browser examples.
- Targets
- App · Binary
- Category
- Official REA: case studies
- Relationship
- Official REA case study
- Sources reviewed
Requirements & limits
- Scope: The documented target is Calculator 11.2508.4.0 x64. The public source commit is an interpretation cross-check, not an identified build commit for that installed DLL.
- Attribution: Function selection was analyst-assisted.
- License: This reconstructs a bounded arithmetic rule, not the Calculator application. Public Microsoft source is MIT-licensed; access and rights to the installed target remain separate.
About this entry
The description was reviewed against primary sources.
Primary sources
- website/evidence/calculator-and-dino.md GitHub · morluto/rea · Revision c360cfc
- https://github.com/morluto/rea/pull/1272
More in Apps
- Feishu: an author-reported isolated second app instance · Case study
- PhotoCraft: editor workflow reconstruction and PSD round-trip boundaries · Case study
- WordCraft: document workflow reconstruction and bounded DOCX compatibility · Case study
- GridCraft: spreadsheet workflow reconstruction and XLSX round-trip limits · Case study
- DeckCraft: presentation workflow reconstruction and bounded PPTX interchange · Case study
- Ledger Reborn: an independent accounting app informed by QuickBooks study · Case study