The phrase emerged from per centum (16th century), and its usage was heavily refined by Italian merchants, who frequently used "per cento" for calculating taxes, interest, and discounts.
A percentage breaks down any quantity into 100 parts, making it a standardized metric for comparison.
Parts per 10,000 (one-hundredth of 1 percent). Per Cent Mille (pcm): Parts per 100,000 (1 in 100,000). per centum
The term evolved over time. "Per" was often abbreviated to "p", and "cento" was contracted until it eventually became the modern symbol: %.
The core, simple formula for a percentage is The phrase emerged from per centum (16th century),
If a whole is divided into 100 parts, a "percentage" indicates how many of those parts make up the subset being discussed.
The term is conceptually identical to one "cent" being 11001 over 100 end-fraction of a dollar, thus 37 cents is 37 percent of a dollar. Deep Mathematical Meaning Per Cent Mille (pcm): Parts per 100,000 (1 in 100,000)
"Percent" (one word) is standard American English, while "per cent" (two words) is more common in British English. How to Pronounce Percent - Deep English