The rule change is a singular noun plural first, so that the classification of students, there are two types of nouns that noun Countable Noun and count nouns Uncountable Noun is not counted.
The rule change is singular to plural nouns to classify the students that there are two types of nouns Countable Noun countable and uncountable nouns Uncountable Noun.
The rule changes are singular nouns plural first, to help students to classify nouns that have 2 type is a word count Countable. Noun and noun count does not Uncountable Noun.