Hung Wan-sheng, a professor of math at National Taiwan Normal University, points out that when the Qing emperor Kang Xi first learned algebra from a missionary in the 17th century, he also had trouble with idea of "multiplying a with a, b with b--they're not numbers and when you multiply them you don't know the value of their product either."
師大數學系教授洪萬生指出，十七世紀清代康熙皇帝初遇耶穌會教士傳入代數時，也有「甲乘甲，乙乘乙，總無數目，即乘出來亦不知是多少」的困惑，跟今日的國中生面臨的困境如出一轍。