1.9*4.5+0.45用简便算法该怎样写
问题描述:
1.9*4.5+0.45用简便算法该怎样写
答
1.9*4.5+0.45
=1.9*4.5+0.1*4.5
=(1.9+0.1)*4.5
=2*4.5
=9