15 8 = (把)(把)拿走拿走8 把,还剩多少把?把,还剩多少把?15 8 = (把)(把)用小棒摆一摆,说说你是怎样想的。用小棒摆一摆,说说你是怎样想的。你喜欢哪种你喜欢哪种方法?方法?7155 = 10103 = 7108 = 2 2 + 5 = 7 8 +( (7) )= 15158 = 715 7 = 813 7 = 6和同学说说你是和同学说说你是怎样计算的。怎样计算的。1. .先圈一圈,再计算。先圈一圈,再计算。12 8 = 414 7 = 7?个?个14 颗颗?个?个16 个个14 8 = 616 7 = 9?颗?颗2. .8 3 = 1111 8 = 38 9 =1717 8 = 97 5 =1212 7 = 53. .13 8 = 516 8 = 811 7 = 44. .147 = 7148 = 6167 = 9168 = 8157 = 8158 = 7137 = 6138 = 5127 = 5128 = 4177 = 10178 = 9117 = 4118 = 35. .