50+1050+1 20+3040+10
60-1050-7 90+88+90
4+5= 5+7= 10+90=
35+2= 4+9= 20+80=
7+3 = 5+6= 30+70=
4+60= 7+7= 100-20=
30-=50-40 28-= 5+3
+2=2+40 60-=7+3
6+72= 40+5= 49+50=
33+60= 24+40= 94+3=
81+10= 37+20= 43+4=
35+4= 62+6= 25+70=
20+(3+6)= 13-(2+4)= 4+(5十30)=
⑴20+8+1 40 ⑵60+20 52
46-4-2 29 40+7 5
28-(5+3) 30 45-40 80
37-(11-4) 20 2+50 47