两位数加两位数进位加法ppt课件.ppt

两位数加两位数（进位）,高渡中心小学刘雅青,用竖式计算,34+12= 23+14=,3 4,+1 2,6,2 3,+1 4,7,46,37,4,3,2.从个位加起。,1.个位和个位对齐，十位和十位对齐。,你知道笔算加法要注意些什么？,集邮大比拼,34枚邮票,16枚邮票,15枚邮票,28枚邮票,羊族,狼族,哪组搜集的邮票最多呢？,34+16=,用小棒摆一摆,羊族：,用计数器拨一拨,用竖式算一算,先用小棒摆一摆,把10根小棒捆成一捆。,34+16=50,个位,十位,10个一是1个十,3,4,4,10,5,0,34+16=50,34 +16 =,50,3 4 1 6 0,个位上4加6得10，个位写0，向十位进1,1,5,从个位加起，满十进一,+,4,34枚邮票,16枚邮票,15枚邮票,28枚邮票,羊族,狼族,哪组搜集的邮票最多呢？,65 +28 =,6,5,8,+,3,1,9,93,2,试一试,笔算加法要注意什么？,2.从个位加起。,1.个位和个位对齐，十位和十位对齐。,3.个位满十向十位进一,45 +29 =,4,5,9,+,4,1,7,74,2,想想做做,53 +27 =,5,3,7,+,0,1,8,80,2,49 +8 =,4,9,8,+,7,1,5,57,9 +61 =,9,1,+,0,1,7,70,6,同学们我计算的正确么？,4,+,2,7,1,3,4,+,2,7,7,6,（ ）,（ ）,2 6,+,3,5,1,5,（ ）,4,+,2,7,1,4,4,+,2,7,1,3,2 6,+,3,5,1,6,1,1,1,对齐,个位,十,一,你还记得运算法则么？,用竖式计算,35+47= 14+56= 74+19= 5+35= 42+38= 26+15= 54+38= 9+43=,27 + 23,50,幢,谢谢欣赏,