11-612-6 8+76+9 11-514-5
13-43+5 14-714-6 13-715-9
9:00时,时针指向,分针指向。
17-=8 11-=6 16-7=
12-=5 -7=8 -4=8
11-5= 15-8= 16-7= 18-9=
12-7= 13-4= 17-8= 15-7=
14-9= 10-2= 12-9= 14-5=
12-8= 11-4= 11-8= 13-8=
11-7=(8)-(4) 14-9=- 16-8=-
12-3=- 15-8=- 13-6=-