You would say "23" as:
Rua tekau mā toru
* Rua: Two
* Tekau: Ten
* mā: And
* Toru: Three
So it translates literally to "two tens and three".
You would say "23" as:
Rua tekau mā toru
* Rua: Two
* Tekau: Ten
* mā: And
* Toru: Three
So it translates literally to "two tens and three".