缘起:儿子是小学三年级的学生,常称自己是班里的“口算大王”。我问他:“‘口算大王’是怎么评出来的呀?”他说:“老师从《口算训练》中选一定数量的口算题让我们比赛,看谁做得又对又快。我常常是最快的,老师和同学都称我是‘口算大王’。”于是我也找了些口算题,测测他一分钟大概能做几道。发现儿子的 Origin: The son is a third-year primary school students, often say that they are in the class “mouth count king ”. I asked him: “How is the word” king of mouth counted “?” “He said:” The teacher selected a certain number of topics from the “mouth training” to let us play and see who did it again and again. Often the quickest, teachers and classmates call me a ’mate of mouth’. “” So I looked for some questions and measured how much he could do in a minute. Find the son