10-913-8 9+819-8
14-813-7 14-716-9
15-914-5 16-815-7
34-6=
先算:
再算:
11-5= 27-3= 30+50= 14-9= 50+16 =
16-8= 45-7= 43-20= 12-4= 14-6 =