,相差多少?,沪教版二年级数学下册,学习目标：1. 使同学们知道数在算线上的排列顺序。2. 能够运用算线熟练正确地解答加减法算式。,算线,小的数在左，大的数在右。,29,19,36,31,57,17+18=,17,27,+10,35,+8,35,17+18=,17,+3,+15,20,35,35,17,+8,25,35,+10,17+18=,17,+20,37,35,35,-2,练习：46+37=,71-28=,71,20,51,8,43,43,71-28=,71,8,63,20,43,43,71,30,41,+2,43,52和34相差多少？,52-34=18,34+（18）=52,52,30,22,4,18,34,+6,40,+12,52,
