Based on common curricula for this textbook version, here is the solved exercise:

The exercise 242 in the 6th-grade textbook by (2005 edition) focuses on the morphology of numerals ( Имя числительное ). In this specific exercise, students are typically required to identify numerals in a text, determine their type, and use them in the correct grammatical form. Exercise 242 Overview

Genitive, Dative, or Prepositional case (depending on the sentence context). Quick Tips for Numerals

Examples often found: пятый (fifth), десятый (tenth), двадцатый (twentieth). Morphological Analysis (Example)

These answer the question "How many?" (сколько?).

Be careful with the soft sign ( ь ) at the end of numerals from 5 to 20 and 30, but in the middle for 50 to 80 and 500 to 900.

For a full step-by-step visual solution, you can check the interactive versions at GDZ.ru or Uchim.org , which host digitized versions of the older 2005-2014 curricula.