口算.5+4= 5-3= 3+0=8+7= 9+7= 7-7=3+5= 10-4= 9-8=7-2= 7-6= 3+7=10-6= 9-6= 9-5=5-4= 8-3= 5+2=
计算:
计算(1) (2)
(1)(2)