An unclear noun may involve number, weight, or measurement. Tamyiz identifies the counted or measured thing.
يَا أَبَتِ إِنِّي رَأَيْتُ أَحَدَ عَشَرَ كَوْكَبًا
My father, I saw eleven stars. كَوْكَبًا tells what was counted.
فَمَنْ يَعْمَلْ مِثْقَالَ ذَرَّةٍ خَيْرًا يَرَهُ
Whoever does an atom's weight of good will see it. خَيْرًا tells what that amount consists of.