9+3=12,12-9=3,快速口算：,11-9= 12-9= 13-9= 14-9= 15-9= 16-9= 17-9= 18-9=,2,3,4,5,6,7,8,9,9+2= 9+6= 9+8= 9+5= 9+3= 9+7= 9+4= 9+9=,11,15,17,14,12,16,13,18,11-9= 14-9= 17-9= 12-9= 15-9= 16-9= 18-9= 13-9=,2,5,8,3,6,7,9,4,2,3,4,5,6,7,8,9,3,4,5,6,7,8,巧算“十几减9”的方法：就是把被减数个位上的数加1就是“十几减9”的差。,11-9=,3+9=,7+9=,15-9=,18-9=,4+9=,17-9=,9+5=,14-9=,2,5,14,12,9,13,8,6,16,抢答：,
