2.4*1.25*0.3和842.4*6.7+8.24*31+0.824*20的简便运算怎么算
问题描述：
2.4*1.25*0.3和842.4*6.7+8.24*31+0.824*20的简便运算怎么算
答
2.4*1.25*0.3
=3×0.8×1.25×0.3
=3×0.3×1
=0.9
842.4*6.7+8.24*31+0.824*20
=8.24×（67+31+2）
=8.24×100
=824