Numerals are classified as a part of speech mainly for practical reasons rather than their linguistic nature. A cardinal numeral expresses an amount of things. Cardinal numerals such as kolme (three) could be regarded as nouns. An ordinal numeral expresses the place of a thing in some order. Ordinal numerals such as kolmas (third) could be regarded as adjectives.
In Finnish, cardinal numerals are inflected and used like nouns, just with some syntactic specialties. Ordinal numerals are inflected like adjectives, applying congruence with the associated noun. For example, we write viides luokka (the fifth class), viidennessä luokassa (in the fifth class), viidensille luokille (for the fifth classes), with congruence in both case and number (singular/plural for the noun).
There are also derivations of numerals that are used like normal nouns, e.g. kakkonen (digit two; number two), as well as adverbs derived from numerals, e.g. kahdesti (twice). Some common types of such derivations are discussed in this chapter.