列式：{#blank#}1{#/blank#}×{#blank#}2{#/blank#}={#blank#}3{#/blank#}

3×8与8×3积相同．

七八五十六    {#blank#}1{#/blank#}、{#blank#}2{#/blank#}、{#blank#}3{#/blank#}、{#blank#}4{#/blank#}

三九二十七    {#blank#}5{#/blank#}、{#blank#}6{#/blank#}、{#blank#}7{#/blank#}、{#blank#}8{#/blank#}

1米-20厘米={#blank#}4{#/blank#}厘米             60厘米+40厘米={#blank#}5{#/blank#}米

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

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