We research the origin of noun-following noun, Hal-Pun-Li which describes rate and clear up the difference between Hal-Pun-Li and numeric nouns which express decimal fractions. Next, we point out the mistakes of encyclopedia of mathematics, the Korean dictionary and the textbook of mathematics in the primary school, related to the difference. And then we detect the problems of the contents in the textbook which cause them. Finally we think of the improvements of the textbook.