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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,*,巧算100以内的加减法,佛山市实验学校 陈月霞,补数关系,两个数相加的和等于,10,，这两个数互为补数。,补数关系,9,1,10,1,9,10,9,的补数就是,1,；,1,的补数就是,9,。,看9想1凑成10,补数关系,8,2,10,2,8,10,8,的补数就是,2,；,2,的补数就是,8,。,看8想2凑成10,补数关系,7,3,10,3,7,10,7,的补数就是,3,；,3,的补数就是,7,。,看7想3凑成10,补数关系,6,4,10,4,6,10,6,的补数就是,4,；,4,的补数就是,6,。,看6想4凑成10,补数关系,5,5,10,5,的补数就是,5,。,看5想5凑成10,补数口决,看,9,想,1,凑成,10,，,看,8,想,2,凑成,10,，,看,7,想,3,凑成,10,，,看,6,想,4,凑成,10,，,看,5,想,5,凑成,10,。,9,加几,10,9,6,15,看,9,想,1,凑成,10,，,加,9,就是减,1,加,10,练一练,9,2,1,1,11,9,7,9,8,9,9,1,6,1,8,1,7,16,17,18,看,9,想,1,凑成,10,，,加,9,就是减,1,加,10,练一练,9,13,1,12,22,9,54,9,25,72,9,1,53,71,1,1,24,63,34,81,8,加几,10,8,6,14,看,8,想,2,凑成,10,，,加,8,就是减,2,加,10,练一练,4,8,2,2,12,8,7,33,8,45,8,2,5,43,2,31,2,15,41,53,看,8,想,2,凑成,10,，,加,8,就是减,2,加,10,7,加几,7,6,13,看,7,想,3,凑成,10,，,加,7,就是减,3,加,10,10,练一练,5,7,2,3,12,4,7,37,7,68,7,1,3,65,3,34,3,11,44,75,看,7,想,3,凑成,10,，,加,7,就是减,3,加,10,6,加几,10,6,6,12,看,6,想,4,凑成,10,，,加,6,就是减,4,加,10,练一练,6,8,4,4,14,6,7,75,6,6,39,4,3,4,35,71,4,13,81,45,看,6,想,4,凑成,10,，,加,6,就是减,4,加,10,5,加几,10,5,6,11,看,5,想,5,凑成,10,，,加,5,就是减,5,加,10,练一练,5,8,5,3,13,5,9,75,5,5,46,5,4,5,41,70,5,14,80,51,看,5,想,5,凑成,10,，,加,5,就是减,5,加,10,计算技巧,进位加：,减补加十。,十几减,9,10,1 1,9,减,9,就是减,10,加,1,1,2,练一练,3,1 2,9,1,4,1 3,9,1,5,1 4,9,1,6,1 5,9,1,7,1 6,9,1,8,1 7,9,1,9,1 8,9,1,减,9,就是减,10,加,1,十几减,8,1 1,8,减,8,就是减,10,加,2,2,3,10,练一练,4,1 2,8,2,5,1 3,8,2,6,1 4,8,2,7,1 5,8,2,8,1 6,8,2,9,1 7,8,2,减,8,就是减,10,加,2,十几减,7,1 1,7,减,7,就是减,10,加,3,3,4,10,练一练,5,1 2,7,3,6,1 3,7,3,7,1 4,7,3,8,1 5,7,3,9,1 6,7,3,减,7,就是减,10,加,3,十几减,6,1 1,6,减,6,就是减,10,加,4,4,5,10,练一练,6,1 2,6,4,7,1 3,6,4,8,1 4,6,4,9,1 5,6,4,减,6,就是减,10,加,4,十几减,5,1 1,5,减,5,就是减,10,加,5,5,6,10,练一练,7,1 2,5,5,8,1 3,5,5,9,1 4,5,5,36,4 1,5,5,减,5,就是减,10,加,5,计算技巧,退位减：,减十加补。,知识回顾,看,9,想,1,凑成,10,；看,8,想,2,凑成,10,；,看,7,想,3,凑成,10,；看,6,想,4,凑成,10,；,看,5,想,5,凑成,10,。,进位加：减补加十。,退位减：减十加补。,不进位加、不退位减的口算方法：,熟记数的组成，用数的组成想结果。,16,10,6,10,6,16,6,10,16,16,6,10,16,10,6,两位数加、减一位数：,一位数加减在个位上。,25,3,25,3,2,8,2,2,两位数加、减整十数：,整十数加减在十位上。,75,20,75,20,9,5,5,5,计算技巧,相同数位上的数相加减：,十位数加减十位数；,个位数加减个位数。,13,6,31,7,8,48,56,6,54,9,28,7,69,5,54,5,56,30,47,30,5,24,89,6,7,56,86,45,29,74,24,62,17,35,83,49,我能行,祝您学习进步！,10,10,10,10,10,
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