案例 :有几瓶牛奶(《北师大新世纪版 ,实验教材第一册)出示情景图 ,抽象出算式9 +5后)师 :谁能想办法找到这个算式的答案?生思考后 ,全班交流)生1 :我是顺着数的10 ,11 ,……14 ;生2 :我是把5分成1和4 ,1和9凑成l0 ,10加4等于14 ;生3 :我也是把一个数凑成10 ,不过 ,我是把9分成 Case: There are a few bottles of milk ("Beijing Normal University New Century Edition, experimental teaching materials first book) to produce scenarios, the abstract formula after 9 +5) Teacher: Who can find a way to find the answer to this formula? Class exchange) Health 1: I was down the number of 10,11, ... 14; Health 2: I put 5 into 1 and 4, 1 and 9 make l0, 10 plus 4 is equal to 14; Health 3: I too Make a number into 10, but I divided 9