When measuring an object, you often get a number that is not an integer. The ancients invented decimal to supplement integer decimal, which is a special form of decimal. Fractions with denominators of 10, 100, 1000 ... can be expressed in decimals. All scores can be expressed in decimals. All decimals can represent the number of components except infinite acyclic decimals. Irrational numbers are infinitely cyclic decimals. According to the decimal bit value principle, decimal fractions are written without denominator, and such numbers are called decimals. The point in the decimal is called the decimal point, which is the dividing line between the integer part and the decimal part of a decimal. The left part of the decimal point is an integer part and the right part of the decimal point is a decimal part. Decimals with zero integer parts are called pure decimals, and those with non-zero integer parts are called decimals.