The numbers 0, 1, 2, 3, and 4 are the first five digits in the decimal number system. 0 represents the absence of quantity, while 1 signifies a single unit. 2 indicates a pair, 3 represents a trio, and 4 denotes a group of four items. These numbers are fundamental in mathematics and everyday counting. In addition to their basic counting function, these numbers are used in various mathematical operations. For example, 0 is the additive identity, meaning any number plus 0 remains unchanged. The numbers 1, 2, 3, and 4 are also used in basic arithmetic, forming the foundation for more complex calculations.