Bug Report: Incorrect Multiplication Results for 4 × 5 and 2 × 3

[JonasHelming]

Bug Report

Describe the bug
A clear and concise description of what the bug is.

To Reproduce
Steps to reproduce the behavior:

1. Click "AC" to clear
2. Click number "4" button
3. Click multiplication "×" button
4. Click number "5" button
5. Click equals "=" button
6. Display shows "9" instead of "20"

Expected behavior
The calculator app should return "20" when multiplying 4 by 5.

Pattern Analysis: It seems like the calculator might be adding instead of multiplying, but even that doesn't match (2+3=5 ✓, but 4+5=9 ✗).

Screenshots (if applicable)
N/A

Environment (please complete the following information):

• OS: [e.g. Ubuntu 22.04 / Windows 11 / macOS Ventura]
• Browser or Runtime: [e.g. Chrome, Node.js, Electron]
• App Version or Commit: [e.g. v1.2.3 or commit abc1234]

Additional context
This appears to be a systematic issue with the multiplication functionality. Two test cases show incorrect results:

• 2 × 3 = 5 (should be 6)
• 4 × 5 = 9 (should be 20)

Both cases should result in correct multiplication operations, indicating a possible flaw in the multiplication logic.