1994 1 1 In the Mathematical Symbols Used in People's Republic of China (PRC) National Standard Physics Science and Technology issued by the State Bureau of Technical Supervision, natural number set was recorded as

N={0， 1，2，3，…}

The original set of natural numbers is called the set of non-zero natural numbers.

N+ (or n *) = {1, 2,3, ...}.

That is to say, there is an element 0 in the high school natural number set.