0.16×9.85＋264×0.0985＋72＋0.985
=0.16×9.85＋2.64×9.85+72＋9.85×0.1
=0.16×9.85＋2.64×9.85＋9.85×0.1+72
=9.85×(0.16+2.64+0.1)+72
=9.85×2.9+72
=9.85×(3-0.1)+72
=9.85×3-9.85×0.1+72
=29.55-0.985+72
=100.565为什么这样做解释一下免得我以后也不会观察都含有985这个数,先整理在一起=0.16×9.85＋2.64×9.85＋9.85×0.1+72 化成同样的含有9.85=9.85×(0.16+2.64+0.1)+72利用加法结合律.整理起来=9.85×2.9+72 >>>>>>>×2.9比较麻烦 化成×(3-0.1) =9.85×(3-0.1)+72=9.85×3-9.85×0.1+72=29.55-0.985+7=100.5654800/12.5/2.5/3.2=？ 简算4800/(12.5×2.5×3.2)=4800/(12.5×3.2×2.5)=4800/(12.5×8×0.4×2.5)=4800/[(12.5×8)×(0.4×2.5)]=4800/(100×1)=4800/100=48有帮助请采纳 谢谢谢谢你你学习一定很棒