8{#blank#}1{#/blank#}7=15      2{#blank#}2{#/blank#}9=18     42{#blank#}3{#/blank#}7=6

36{#blank#}4{#/blank#}4=9      8{#blank#}5{#/blank#}7=56     90{#blank#}6{#/blank#}9=81

7×{#blank#}1{#/blank#}=21         45÷{#blank#}2{#/blank#}=5          3×{#blank#}3{#/blank#}=21

{#blank#}4{#/blank#}×5=20        36÷{#blank#}5{#/blank#}=9         {#blank#}6{#/blank#}×2=18

28÷{#blank#}7{#/blank#}=7        2×{#blank#}8{#/blank#}=12         {#blank#}9{#/blank#}÷{#blank#}10{#/blank#}=1