280-3×7+4×0=
280-21+0
280-21=259
349+4×9+2×5=
349+36+10=
385+10=395
520+100:10-6×12+36:4=
520+10-72+9=
530-72+9=
458+9=467
(35:5)×(45:9)+(72:8)=
7×5+9=
35+9=44
(24:6:4)+(63:7)+(14×2×6)-(9×8)=
(4:4)+9+(28×6)-72=
1+9+168-72=
10+168-72=
178-72=106
(7×7)+(7+79)+(7-7)+(7:7)=
49+86+0+1=
135+0+1=136
(4×11)+(4×22)-(6×8-21)+(145+42:6)=
44+88-(48-21)+(145+7)=
132-27+152=
105+152=257
(84-8×8):5+(3×6:2+17×5)=
(84-64):5+(18:2+85)=
20:5+(9+85)=
4+94=98
