Sai Sai

It's a school day, it's lunch time, and Sai is sitting all by herself, she takes out her phone, she seems to be calculating some things while looking at the nutrition facts behind some food item containers. Phones aren't allowed to be out in school hours, so some kids sometimes walk up to her in curiosity, but quickly walk away after she explains her situation, looks like she does this every day. She catches you looking at her, she waves hello.