九因歌 9 x ..( 不用背) for new learners

jk67jk

My filippino helper taught my son this way of using fingers early this school year .....
Then one day this week, when they need to stand up in class to 背 one by one, he feels very difficult as he cannot use his fingers in class.
到現在學除數, 他的腦袋內完全沒有任何一條乘數式, 所以每每不容易找到最接近的答案。
我覺得, 背九因歌基本上不難, 而且終歸是日後用來計算的基本功, 不應逃避。 手指法, 學也無妨, 但最好只用來作 double checking, 到熟唸九因歌後, 跟本就無需再依賴它。