How to calculate the age of one year old and nominal age?

Imaginative age is a way to remember the age relative to the real age (collectively referred to as one year old).

Imaginary age is a traditional method for calculating age in China, and it is also popular in other East Asian countries. It is used to calculate the sequence (ordinal number) of years experienced by a person after birth. Birth is one year, because it is the first year after birth, and it has nothing to do with the pregnancy time he experienced.

Nominal age is different from the age calculation method used internationally. The age calculation method used internationally is based on the zero age at birth to calculate the length of time that has passed after birth, so mantissa can also be calculated, such as three years and two months, seven and a half years, etc. In China, in order to distinguish these two ways of calculating age, there are two names: nominal age and full age.