文档介绍：26+8=         63-7=         47+6=       42+40+5=
  7×6=         7×7=         7×8=          7×9=
  2×5=         3×5=         4×5=          5×5=
 81-5=         45+25=       100-9=      78+9-20=
  5×6=         5×7=         5×8=          5×9=
      9×6=        9×7=         9×8=          9×9=
      48+9=        50-3=        26+25=      25-15+30=
      6×5=        7×5=         8×5=          9×5=
      6×1=        6×2=         6×3=          6×4=
      68-32=       84+7=        49-18=      68-14-30=
      3×6=        3×7=         3×8=          3×9=
      8×1=        8×2=         8×3=          8×4=
      83+17=       54-5=         16+60=      48-7-20=
      6×6=        6×7=         6×8=           6×9=
      9×1=        9×2=         9×3=