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#}

①1.76÷0.25÷0.4

②4.68÷（22-14.2）

③6.9×1.6+8.4×6.9

④1.6×0.75+1.8÷1.5

⑤24.5+5.5÷0.5

①32×2.5×1.25

②5.56×0.45+5.56×0.55

③0.375÷0.25×4

④68.5÷25÷0.4

⑤15.8-4.9÷2

⑥2.7×[（3.2+6.8）÷0.25]