3.12×0.5＝{#blank#}1{#/blank#}×{#blank#}2{#/blank#}

12.5×8.7×0.8＝({#blank#}3{#/blank#}×{#blank#}4{#/blank#})×{#blank#}5{#/blank#}

(2.5＋0.6)×4＝{#blank#}6{#/blank#}×{#blank#}7{#/blank#}＋{#blank#}8{#/blank#}×{#blank#}9{#/blank#}

4.1×1.5＋5.9×1.5＝({#blank#}10{#/blank#}＋{#blank#}11{#/blank#})×{#blank#}12{#/blank#}

12×8×125=12×（{#blank#}1{#/blank#}×{#blank#}2{#/blank#}）

6.2+17.9+3.8=（{#blank#}3{#/blank#}+{#blank#}4{#/blank#}）+17.9

42×11+11×58=（{#blank#}5{#/blank#}+{#blank#}6{#/blank#}）×{#blank#}7{#/blank#}

50.27-6.03-1.97=50.27-（{#blank#}8{#/blank#}+{#blank#}9{#/blank#}）

22.36﹣0.48﹣6.52     2.3×12.5+0.58×125﹣1.25            36×（+-）