× {#blank#}1{#/blank#} 

× {#blank#}2{#/blank#} 

÷ {#blank#}3{#/blank#} 

25÷ {#blank#}4{#/blank#}25×5．

{#blank#}1{#/blank#}      108÷ {#blank#}2{#/blank#}108     {#blank#}3{#/blank#}

0.5÷0.9{#blank#}1{#/blank#}0.5                0.55×0.9{#blank#}2{#/blank#}0.55

36÷0.01{#blank#}3{#/blank#}3.6×100          7.3÷0.3{#blank#}4{#/blank#}73÷3

84÷2={#blank#}1{#/blank#}            420÷10={#blank#}2{#/blank#}        420÷20={#blank#}3{#/blank#}