一七得七       五七三十五

 1×{#blank#}1{#/blank#}=7   {#blank#}2{#/blank#}×7=42    {#blank#}3{#/blank#}×7=28

7×{#blank#}4{#/blank#}=49    7×{#blank#}5{#/blank#}=42    7×{#blank#}6{#/blank#}=28

7＋7＋7={#blank#}1{#/blank#}×{#blank#}2{#/blank#}={#blank#}3{#/blank#}

8×9=         6×6=          4×7=         6×3=

7×6=         9×4=          8+9=          4×8=

9×7=         8×8=          3×5=         2×7=

9×9=         3+5=           1×6=          5×4=

①5×8-3=37(个)                           
②5×7+2=37(个)                           
③2×8=16(个)   3×7=21(个)   16+21=37(个)