The unit is the digital unit of measurement. We usually use decimal notation. The so-called decimal refers to the relationship between every two adjacent counting units: one large unit equals ten small units, that is, the forward speed between them is "ten".

Calculation is a mathematical term, and it is a thinking process that transforms a single or complex input value into a single or complex result. The definition of calculation can be used in many ways, from a fairly precise definition, such as "arithmetic" using various algorithms, to a more abstract definition, such as "calculation of strategy" or "calculation of the success probability of the relationship between two people in the competition".