文档介绍：8 + () = 12 8 + () = 14 8 + () = 15 8 + () = 17 4679 8 + () = 13 5 8 + () = 16 8 算一算十几减 8 科目:数学年级:一年级教者:闫娜因为 8+7 =15 所以 15-8=7 15-8 = ? 方法 1想加算减 1 11 – 8 = 想: 8 加( )得 11 33 11 减 8 得3 方法 2 15 - 8 5 10 = 7破十法:先分再减后加 2 15-8 = ? 3 12 - 8 = □想: 8 加( )得 12 4 4 16 - 8 = □想: 8 加( )得 16 8 8 14 - 8 = □6 17 - 8 = □9 4想一想做一做 2 13 - 8 = □想: 8 加( )得 13 55 15 - 8 = □想: 8 加( )得 15 77 想一想,算一算操作练习 4 12 - 8 = 14-7= 7 12 - 8 = 4 14-7= 7 11-8= 12-9= 13-8= 14-9= 15-8= 16-9= 17-8= 19-8= 10-9= 19-9= 1335 5 77911 10 17-9= 8 14-8= 6 12-3= 11-5= 13-7= 14-6= 18-5= 16-2= 96 681314