口算
27+30= 50+20=
37+9=
58-8=
82-70= 7+63=
76-60= 72-7=
28+50= 55+5=
37-8= 16+70=
5+63= 81-8=
75-20= 13-6=
85-9= 65-5= 4+85= 9+39=
8+5= 19-9=
17-6=
36+6=
90+10= 80-5= 4+28= 71+9=
53-8= 57+7= 5+85= 44+8=
9+33= 72-5= 80-7= 8+42=
89-70= 58-6= 62-9= 46-7=
29+9= 92-9= 85+6= 30+58=