When young children (or new Muslims) are learning the Quran, they don't often start at the beginning and work their way through. After reading the first surah (Al-Fatihah), they usually then go to the end of the Quran and learn Juz' Amma, the final section of the Quran which consists of many shorter chapters. These shorter chapters are often used in prayers, and are the easiest to learn at the beginning.
good. need to tell which surah its start of juzuk amma