Multiplication of Directed Numbers 有向數的乘法

Explore the rule of multiplication of directed numbers through changes in temperature. (for use with the Class Activities on P.2.33 and P.2.34 of Book 1A) 透過温度的變化，探究有向數乘法的計算法則。 (1A 冊第 2.33 及 2.34 頁的課堂活動適用)