58+= 65-=
74+= 87-=
+41= -4=
+62= -9=
15-6= 11-4= 17-9= 70-6=
32+50= 20+30= 58+9= 60+8=
98-8= 12+5= 70+20= 19+5=
40+10= 50+20= 70+17= 80-50=
28+12+16= 80-40+35= 75-5-50= 45+12-20=
①57.6﹣18.15+32.4﹣11.85
②78×25+1764÷49
③2.5×32×12.5
④3.6×[(37.5+18.5)÷2.8]
⑤÷[(﹣)×]
⑥199×99+178+21