{#blank#}1{#/blank#} ×7＜42      5×{#blank#}2{#/blank#}＜41     9×{#blank#}3{#/blank#}＜80      {#blank#}4{#/blank#}×9＜7×6

三{#blank#}1{#/blank#}二十一   五七{#blank#}2{#/blank#}   四七{#blank#}3{#/blank#}

两个乘数都是7，积是{#blank#}1{#/blank#}？

{#blank#}1{#/blank#}七三十五

五{#blank#}1{#/blank#}三十   {#blank#}2{#/blank#}七三十五     {#blank#}3{#/blank#}五二十  

三{#blank#}4{#/blank#}二十七  四八{#blank#}5{#/blank#}   二{#blank#}6{#/blank#}十八

6×3＝                      2×1＝                       14＋8＝                      4×6＝

3×7＝                      5×9＝                       3×8＝                         74－20＝