PowerToys Run Calculator incorrect result on basic multiplication/division operation

[minig0d]

Microsoft PowerToys version

0.88.0

Installation method

PowerToys auto-update

Running as admin

Yes

Area(s) with issue?

PowerToys Run

Steps to reproduce

Type in "399.95/5020" or "=399.95/5020" (without the quotes). It's giving a result of 159.98.

If I change it to"399.95/(5020)" or "=399.95/(5020)", the correct result of 0.39995 is returned.

✔️ Expected Behavior

the correct result of 0.39995 is returned

❌ Actual Behavior

It's giving a result of 159.98.

Other Software

No response

[similar-issues-ai]

We've found some similar issues:

• Calculator in PowerToys Run making mistakes when number with too many digits after decimal point is involved #15636 , similarity score: 83%
• Multiplication Error #28115 , similarity score: 83%
• Decimal Formatting (,/.) breaks calculations #33890 , similarity score: 82%
• Wrong math calculations #27697 , similarity score: 82%
• Incorrect handling of the point in calculations #25633 , similarity score: 81%
• Calculator bug #28400 , similarity score: 81%
• power toy run doesn't displays two 0 in the result of a ecuation #31341 , similarity score: 81%
• Calculation issue #36814 , similarity score: 81%

If any of the above are duplicates, please consider closing this issue out and adding additional context in the original issue.

Note: You can give me feedback by 👍 or 👎 this comment.

[minig0d]

I reviewed the issues that the AI bot found and I don't believe any of them are the same issue. I tested the math in them and all of them work fine for me. Almost all of them appear to be because of some type of error with the Language/Regional settings (the computer set to a language that uses the comma as a decimal separator). My issue is occurring on an US English language windows 10 install.

[daverayment]

Hi @minig0d. This is because the order of mathematical operations follows the standard BODMAS rule, where Brackets are evaluated before Division or Multiplication. The difference between your two examples is that in the second, the 50 * 20 is evaluated before the division, so 399.95 is divided by 1000. In the first example, 399.95 is divided by 50 and then that result is multiplied by 20.

Any calculator will give you the same answers. For example, Windows Calculator in Scientific mode:

Without brackets:

With brackets:

[minig0d]

Hi @minig0d. This is because the order of mathematical operations follows the standard BODMAS rule, where Brackets are evaluated before Division or Multiplication. The difference between your two examples is that in the second, the 50 * 20 is evaluated before the division, so 399.95 is divided by 1000. In the first example, 399.95 is divided by 50 and then that result is multiplied by 20.

Eek... I knew that... brainfart sorry!