一年级上册数学课件-9.2 不退位减法 冀教版 (共31张PPT)

课件31张PPT。十几减几引 入引入:15 – 9 =口算17 – 9 =11 – 9 =13 – 9 =19 – 9 =682410新授探究一探究二探究一:探究一探究二13 – 8 =5想：8 + ( 5 ) = 13
13 – 8 = 5想：10 – 8 = 2
2 + ( 3 ) = 5探究一探究二探究二:1、口算。16 – 8 =11 – 8 =15 – 8 =15 – 7 =8378探究一探究二11 – 6 =16 – 7 =11 – 5 =16 – 9 =5967探究二:２、口答练习。探究一探究二11 – 6 =16 – 7 =11 – 5 =16 – 9 =5967探究二:２、口答练习。探究一探究二11 – 6 =16 – 7 =11 – 5 =16 – 9 =5967探究二:２、口答练习。探究一探究二11 – 6 =16 – 7 =11 – 5 =16 – 9 =5967探究二:２、口答练习。探究一探究二３、看谁看得又快又好。探究二:12 – 3 =13 – 7 =12 – 9 =13 – 6 =963712 – 5 =16 – 8 =12 – 7 =14 – 7 =7857练习练习一练习二练习一练习二练习一:1、看图列式计算。练习一练习二练习一:1、看图列式计算。48486767练习一练习二练习一:2、口算。11 – 4 =13 – 4 =11 – 3 =13 – 7 =14 – 8 =12 – 6 =17 – 8 =14 – 7 =练习一练习二练习一:2、口算。11 – 4 =13 – 4 =11 – 3 =13 – 7 =14 – 8 =12 – 6 =17 – 8 =14 – 7 =11 – 7 =74练习一练习二练习一:2、口算。11 – 4 =13 – 4 =11 – 3 =13 – 7 =14 – 8 =12 – 6 =17 – 8 =14 – 7 =11 – 7 =13 – 9 =7944练习一练习二练习一:2、口算。11 – 4 =13 – 4 =11 – 3 =13 – 7 =14 – 8 =12 – 6 =17 – 8 =14 – 7 =11 – 7 =13 – 9 =14 – 6 =796448练习一练习二练习一:2、口算。11 – 4 =13 – 4 =11 – 3 =13 – 7 =14 – 8 =12 – 6 =17 – 8 =14 – 7 =11 – 7 =13 – 9 =14 – 6 =12 – 6 =79664486练习一练习二练习一:2、口算。11 – 4 =13 – 4 =11 – 3 =13 – 7 =14 – 8 =12 – 6 =17 – 8 =14 – 7 =11 – 7 =13 – 9 =14 – 6 =12 – 6 =11 – 8 =7986644386练习一练习二练习一:2、口算。11 – 4 =13 – 4 =11 – 3 =13 – 7 =14 – 8 =12 – 6 =17 – 8 =14 – 7 =11 – 7 =13 – 9 =14 – 6 =12 – 6 =11 – 8 =13 – 6 =798666443786练习一练习二练习一:2、口算。11 – 4 =13 – 4 =11 – 3 =13 – 7 =14 – 8 =12 – 6 =17 – 8 =14 – 7 =11 – 7 =13 – 9 =14 – 6 =12 – 6 =11 – 8 =13 – 6 =17 – 9 =79866694437868练习一练习二练习一:2、口算。11 – 4 =13 – 4 =11 – 3 =13 – 7 =14 – 8 =12 – 6 =17 – 8 =14 – 7 =11 – 7 =13 – 9 =14 – 6 =12 – 6 =11 – 8 =13 – 6 =17 – 9 =14 – 7 =7986669744378687练习一练习二练习二:练习一练习二13只苹果，其中红苹果有8只，绿苹果有几只？练习二:练习一练习二练习二:13只苹果，其中红苹果有8只，绿苹果有几只？练习一练习二练习二:13只苹果，其中红苹果有8只，绿苹果有几只？13 – 8 = 5(只)练习一练习二练习二:13只苹果，其中红苹果有8只，绿苹果有几只？13只苹果，其中绿苹果有5只，红苹果有几只？13 – 8 = 5(只)练习一练习二练习二:13只苹果，其中红苹果有8只，绿苹果有几只？13只苹果，其中绿苹果有5只，红苹果有几只？13 – 8 = 5(只)13 – 5 = 8(只)小结: 今天这节课我们学习了《十几减几》，知道计算十几减几仍可以采用“想加算减”的方法和“破十减的方法”；还知道了一道减法算式可以改写成另一道对应的减法算式。这样的思想也能帮助我们计算十几减几。作业：