I noticed the other day that you can type "1+1 sq ft in sq in=" and macOS will helpfully autocomplete the answer: 1,694.0031 square inches. Which is completely wrong. 2 square feet is 288 square inches. It took a few minutes to solve the puzzle of what the hell it is doing.
So take caution trusting Apple's math, which naturally is up to 2x better³—for some value of x.
I had the same issue with a different calculation. The answer was wrong.
I thought it looks weird because I put a space after the = and the autocomplete does not add that.
The order of operations here is quite ambiguous. It’s not obvious even to a human reader how you would expect this to be interpreted.
<expression without units> [<unit> [in <unit>]]
<expression with units> [in <unit>]
Of course the appropriate care must be paid to interpreting "in" correctly as either a unit or a keyword.
Fun puzzle. Spoilers ahead:
It seems it’s considering the first 1, and not the second, to be in square meters. “(1+1) sq ft in sq in” works.
If you type too quick, it misses numbers.
If you type too many times “+” it add too many times
If you try to use it as old standalone calculator, things does not calculate right.
It is hard to clear numbers.
Just so stupid.
In aggregate, people will choose to submit the option that abuses users less. Xcancel keeps the original X link unobstructed if you need it for some reason.