68=+8 40+=47 56-=6
75=5+ +60= 63 48-=40
34=+30 4+=44 100-=80
①+= ③ -=
②+= ④ -=
10+4=
14-4=
20-8=
30+4=
54-4=
28-8=
4+30=
50-4=
20+8=
80+7= 20+9= 30-5= 70-8= 40-6=
15-8=
44+9=
50+8=
20+3=
9+20=
58-8=
8+80=
1+70=
45+8=
3+70=
5+30=
85-80=
9+7=
70+8=
14-8=
填空。
+ = + =
- = - =