用简便方法计算 0.28×8.6+7.2×0.86 999×778+333×666 怎样写?
问题描述：
用简便方法计算 0.28×8.6+7.2×0.86 999×778+333×666 怎样写?
答
0.28×8.6+7.2×0.86
=0.28*8.6+0.72*8.6
=(0.28+0.72)*8.6
=1*8.6
=8.6
999×778+333×666
=999*778+333*3*222
=999*(778+222)
=999*1000
=999000