Wikipedia sayings about when reporting the answer to a mathematical calculation involving addition or subtraction, how does one determine the number of significant digits to report in the answer?

1.List of Egyptian inventions and discoveries

problem of the Moscow Mathematical Papyrus asks for a calculation of the surface area of a hemisphere (Struve, Gillings) or possibly the area of a semi-cylinder

https://en.wikipedia.org/wiki/List of Egyptian inventions and discoveries

2.General der Nachrichtenaufklärung

deal of non-carrying addition or subtraction had to be done. Note: little information is available from TICOM as to how this device functioned. The Finnish

https://en.wikipedia.org/wiki/General der Nachrichtenaufklärung