In mathematics, the purpose of carry counting system is to represent infinite numerical values with limited numerical symbols. Theoretically, any number can be used as the base, just input one every n numbers, and even irrational numbers can be used as the base. For example, every step, there is data showing that the computer is most efficient when it takes the transcendental number E as the base.

There are many decimal systems in human history, such as the hexadecimal system of half a catty, the hexadecimal system of two instruments and four images that produce gossip, the decimal system of more than a dozen flowers, the hexadecimal system of 1 hour 60 minutes, the hexadecimal system of 1 seven days a week, the hexadecimal system used for gambling dice and so on.

If the computer uses binary because the diode, the main component of the computer, can easily construct NAND gate circuits from the beginning, then the most popular decimal system of human beings should be because of the main component of human beings.

I asked my daughter, what is 3 plus 4? The daughter held out three fingers in her left hand and four fingers in her right hand, counted them and said "7". I ask again, how much is 4 plus 5? The daughter stretched out one more finger in each hand, counted it and said "9". I keep asking, what about five plus six? The daughter looked at her hand and said doubtfully, "I don't have six fingers." I know that five plus five equals ten! " "When she spoke, her daughter held out the last finger.