Por que a SEFAZ rejeita sua NF-e (e a culpa é do IEEE 754)

Brazil's SEFAZ tax authority rejects electronic invoices (NF-e) when product totals diverge even by R$0.01, caused by IEEE 754 floating-point representation errors in languages like JavaScript, Python, and C. The article explains how decimal values like 1.064 are stored inexactly in binary, leading to drift that accumulates through multiplication and division—common in industries where unit prices are derived from package divisions. The solution involves using string-based or decimal arithmetic instead of native floating-point to achieve exact decimal calculations required by fiscal systems.