Microsoft/calculator

Entering negative exponents in Scientific mode is not supported

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#1311 opened on Jul 12, 2020

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Area: User ExperienceBugPri: 2help wantedtriage approved

Description

Describe the bug The Calculator app does not support entering negative exponents. For example, in the Scientific mode, we can enter "2.6e2" produces the expected output 260 but trying to type "2.6e-2" does not give 0.026 as it should. I even tried to put the -2 within parentheses to make sure it understands that the dash symbol is not for subtraction here but even that fails.

Steps To Reproduce

  1. Open the Calculator app in Scientific mode.
  2. Type "2.6e-2" and attempt to calculate it.
  3. The answer reported back is 0.6 instead of the expected 0.026.

Expected behavior The Calculator app should ideally support entering negative exponents and on typing "2.6e-2" in Scientific mode, it should understand that a dash following an exponent symbol 'e' is not supposed to mean subtraction but a negation.

Screenshots image

Device and Application Information

  • OS: Windows 10 Home Insider Preview Single Language
  • OS Build: 10 - 0 -20161 - 0 (20161.rs_prerelease.200627-1754)
  • Architecture: x64
  • Application Version: 10.2005.23.0

Requested Assignment I'm just reporting this problem. I don't want to fix it.

Contributor guide

Tech stack
cpp
Domain
desktop
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
C++ experienceWindows development setupUnderstanding of number parsing
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
65
Research direction
The bug is about entering negative exponents in Scientific mode. The issue is in the expression parser, likely in the tokenization or number parsing logic. Look for how the 'e' character is handled and why a negative sign after 'e' is interpreted as subtraction rather than a negative exponent. Files like 'CalculatorManager.cpp' or 'ExpressionCommand.cpp' may contain the relevant code. The maintainer has not yet provided specific guidance, but the bug report is clear and reproducible.