For one thing all-day classes begin in fifth grade, and children don't have that much spare time. Also, starting in fifth grade math problems shift from stressing calculation to stressing thinking, so that the Kumon method of rehearsed calculating is strained.
一方面小學五年級開始功課漸重，孩子不再有多餘的時間上各種才藝班；另方面五年級開始數學明顯地由計算課程進入重思考性的階段，全是計算式演練的功文數學便面臨考驗。