這是本號的第3篇推送。
今天,用中英雙語,為二年級的露西講解「雞兔同籠」的數學題(Chicken-and-Rabbit Problems)。
我們先看下題目:
English: 4 chickens and rabbits have 10 legs altogether. How many chickens are there? How many rabbits are there?
中文:雞和兔共4隻,腿共10條。有幾隻雞,幾隻兔?
We can solve this problem by drawing.
Step 1: We draw 4 circles to represent 4 animals. Assume all were chickens.
第1步:可以畫4個圓圈來代表4個動物。假設它們全是雞。
Step 2 : Each chicken has 2 legs. So there were 8 legs, and 2 more legs are needed to add on.
第2步:每隻雞有2條腿,那麼,一共有8條腿,還需要加2條腿。
Step 3 : Just add the 2 legs to any one of the circles. Those who have 2 legs are chickens, while those who have 4 legs are rabbits. So there are 3 chickens and 1 rabbit.
第3步:把2條腿加到其中1個圓圈裡就可以啦!2條腿的是雞,4條腿的是兔。所以,一共是3隻雞、1隻兔。
題目中的詞彙:altogether,意思是「一共」。
題目中的句型:How many ... are there? 意思是有多少個……?
題解中的詞彙:represent,意思是「表示,代表」;assume,意思是「假設」。
English: A spider has 8 legs. A dragonfly has 6 legs. 6 spiders and dragonflies have 40 legs altogether. How many dragonflies are there?
中文:1隻蜘蛛8條腿,一隻蜻蜓6條腿。蜘蛛和蜻蜓共6隻,腿共40條。有多少只蜘蛛,多少只蜻蜓?
露西是個小學生
拒絕焦慮 拒絕雞湯
科學養娃 理性雞娃
Terry Chew. <Maths Olympiad: Unleash The Maths Olympian In You!> Junior 1. Singapore Asia Publishers Pte Ltd.