ڑ is one of Urdu's retroflex letters and the most physically distinct sound in the alphabet for many learners. The tongue does not just touch the roof of the mouth; it flicks against it. The toay is what marks this on paper. Children sometimes write ر because the body looks the same; ask them to feel where the tongue is when they say پڑھنا versus پر, and the difference becomes audible. ڑ also never starts a word; it only appears in the middle or at the end.

When your child writes لڑکا and پڑھنا correctly with ڑ, they are writing the words of their own life: their friends, the act of reading itself. The toay is small, but it is the proof that this script belongs to them.