Surah Taha is known to cool down anger and soften the heart. It was the surah that Saidina Umar (r.a), while in the state of anger, had listened to, before he embraced Islam.
The children are taught to memorize verses 1 to 5 of the surah and MasyaAllah, it did not take long for them to be able to recite the verses. Listen to the beautiful little voices reciting Surah Taha verse 1 to 5.
*Reference for the verses can be found at http://quran.com/20