Short answers, pulled from the story.
Decimal notation is a base-10 numeral system that uses ten digits from 0 to 9 to represent numbers. It functions as a positional system where the value of a digit depends on its place within the number, allowing for the precise representation of both integers and non-integer values.
The positional decimal system first emerged in China during the Warring States period, evidenced by the world's earliest known decimal multiplication table carved onto bamboo slips around 305 BCE. Ancient cultures from the Indus Valley to Egypt utilized decimal ratios in their standardized weights and rulers as early as 3000 BCE, though these early systems were non-positional.
The decimal point was popularized by John Napier in 1620, who introduced the period as the decimal separator in his posthumous publication on logarithms. Simon Stevin published his influential booklet De Thiende in 1585, arguing for the practicality of decimal fractions in trade and science before Napier's work.
The decimal system became the global standard due to its alignment with human biology, specifically the ten fingers on two hands, and its efficiency in notation. It allows for the precise representation of uncertainty and enables the complex calculations required to build infrastructure or balance national budgets.
Modern computers operate internally on a binary system of zeros and ones, converting decimal values to binary for processing and back to decimal for human display. This conversion is not always precise, leading to errors in financial calculations where binary floating-point arithmetic cannot represent decimal fractions like 0.1 exactly.