A decimal is a numerical system based on powers of ten, where numbers are expressed using a dot (or decimal point) to separate the whole part from the fractional part. It is not an SI unit but is widely used in both customary and metric systems.
The decimal system has roots dating back to ancient civilizations. The earliest known use was by the Egyptians around 3000 BCE. The Chinese adopted it around 500 CE. The modern decimal system was popularized in Europe during the Renaissance, notably through the work of mathematicians like Simon Stevin in the late 16th century.
Decimals are commonly used in everyday life for financial transactions, measurements, and statistics. In science and engineering, decimals facilitate precision in calculations. They are universally understood across many countries, especially in commerce and education.