［教学实录］１ .提出问题 ,导入新课师 :(板书４２÷２)４２÷２等于多少 ?(学生纷纷举手 ,师指名回答。 )生 :等于２１。师 :你是怎么想的 ?生 :４０÷２＝２０,２÷２＝１ ,２０+１＝２１。师 :大家有不同意见吗 ?(学生表示没有 )如果要用竖式来计算这道题目 ,你们打算怎么 [Teaching Record] 1. Ask a question and import a new lecturer: (板 書 42 ÷ 2) 42 ÷ 2 Equal to how many? (Students have raised their hands and their names have been answered.) Student: Equal to 21. Teacher: What do you think? Students: 40 ÷ 2 = 20,2 ÷ 2 = 1, 20 + 1 = 21. Teacher: Do you have different opinions? (Student said no) If you want to use vertical to calculate this problem, how are you going to plan