What is a Numeral Adjective?

A numeral adjective is a word that tells the number or frequency of a noun.

Examples:

1. Two parrots were sitting on a branch of the mango tree
2. Thirty days make a month.
3. Most children are innocent at heart.
4. The last day of the month is a half-working day in schools.
5. Just a few soldiers sometimes win a battle.

The words, Two, Thirty, Most, last and a few, in the above examples show the
number or the frequency of their respective nouns. Therefore, they are numeral adjectives.