一年级数学上册第9单元20以内的减法(12减几)教学.ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,12,减 几,教学目标,1,、结合具体情境，经历分析问题、列出算式、并尝试计算,12,减几的过程。,2,、会用“想加算减”的方法计算,12,减几的减法，能正确进行计算。,3,、能主动与同学交流自己的算法，初步体会加减法各数之间的关系。,岸上有几只鸳鸯？,点数法：,画出,12,个花片，去掉,4,个，还剩,8,个。,12,4 =,2,2,10,8,12,4 =,2,10,6,8,=,12,6,6,1.,看图列式计算。,练一练,+=,=,=,9,2,11,11,9,2,11,2,9,+=,=,=,5,7,13,13,5,7,13,7,5,2.,算一算。,11,8 =,8,3 =,11,3 =,12,5 =,5,7 =,12,7 =,11,3,8,12,7,5,12,9 =,3,9 =,12,3 =,12,3,9,3.,算一算。,9,8,7,6,5,4,3,3,4,5,6,7,8,9,4.,飞机该停在哪里？,12,8,11,6,11,5,12,5,12,4,4,5,6,7,8,过荷塘,5.,填一填。,12,8 =,6,7 =,11,5 =,12,4 =,7,5 =,5,8 =,13,4,6,8,12,13,12,6 =,3,9 =,7,6 =,12,6,13,