文档介绍：138-89=        5400÷54= 200×34=        550-450=         18000÷600= 2700÷30=    45×14=         18万+24万=          89÷100=          +=         73×1=           ×10=         4÷10=             17÷1000=               +=           80×25=             1-=           ×100=       +99=            100÷25=                  90-=               41×100=         8800÷400=      ×10=600÷30=          ÷100=             150+70=            356-98=             125×8=        612÷6=         12×80=           ×100=               840÷40=          ×100=        8÷100=   +=         +=       +=                 -=             1-=              ÷10=          ++=     5×17×2=        154-73-27=            1000×25=          24×0÷12=         ×100=      ÷10=×10=          ÷100=       ÷1000=     300÷15=           ×1000=    14×60=          5400÷600=      345+298=  +=          -=        +=       -=           -=     -7=           +=        1-=                310×5×2=        4×(25+50)=      +19= ÷17=     240÷30= 1000×=        += 8×125= += 7-= -= 99×23= 50×4= 5÷1000=         += 10×= 65×25×4= ÷100= -=   += 1-= 231-99=          +=       32+268=  -=        +=      7×99+7=        24-19+24+19=     -=      -=        120÷6÷2=      9100÷70=  4×(36-25)=       1-=           +=        300-84-16=        2-=       145-99=          102×5=   ×60= +=         -=       ×400=       +=         60÷=       2-=          457+198=       756-197= 45+15-45+15=      --=     ÷=       5××=       ×3=        +=        400÷25÷8=    7÷=416÷8=           ÷30=         ×3×8=      -=         821-202=      ÷50=         ×5=       125×16= 7×(10+)=          (+)÷9=          -(+)=