رَأَيْتُ أَحَدَ عَشَرَ طَالِبًا — I saw eleven students.
رَأَيْتُ: past verb plus a connected subject pronoun in the nominative position.
أَحَدَ عَشَرَ: compound numeral fixed on fatḥ in both parts, in the accusative position as direct object.
طَالِبًا: accusative tamyīz.
Compared with the preceding sentence, the whole numeral’s syntactic role has changed, but its internal endings have not.