Why doesn't windows calculate negative numbers. - Microsoft Community
Calculate Percentage Change for Negative Numbers in Excel - Excel Campus
Something mildly interesting about the iPhone calculator: Negative Zero : r/mildlyinteresting
Will Davis on Twitter: "You'll also see the “negative zero” bug on lots of old, or later cheap, calculators. Nothing tells the calculator to remove the sign on a zero result. Get
Use a calculator to evaluate expressions with directed numbers | Level 5 Maths | NZ Level 5 | Mathspace
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