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.
Requirements and limitations
- 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.
- Function selection was analyst-assisted; the illustrative agent conversation is not a recording of fully autonomous discovery. No PDB symbols were loaded.
- Microsoft source tests were inspected, not run, and no completed Windows GUI input check is claimed. Browser checks exercise the explanatory examples only.
- 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
- Type
- Case study
- Category
- Official REA: case studies
- Relationship
- Official REA case study
- Targets
- App · Binary
Sources reviewed
The description was reviewed against primary sources. This does not establish runtime testing, security auditing or verified compatibility.