Daily Chinese Idiom Guessing Game
Refers to something common or routine, like a daily occurrence.
指家中日常的饭食。也比喻常见的事情。
唐·宋若华、宋若昭《女论语·事夫章》莫教寒冷，冻损夫身；家常茶饭，供侍殷勤。”宋·罗大经《鹤林玉露》卷四常调官好作，家常饭好吃。”
For her, solving complex math problems is just a common occurrence.