1.2乘9.9乘2.5的怎么简便运算

问题描述:

1.2乘9.9乘2.5的怎么简便运算

1.2*9.9*2.5
=0.3*4*2.5*9.9
=0.3*(4*2.5)*9.9
=0.3*10*9.9
=3*(10-0.1)
=30-0.3
=29.7