70.1-41.89+2.78怎样简便运算(快点)
问题描述:
70.1-41.89+2.78怎样简便运算(快点)
答
70.1-41.89+2.78
=70.1+2.78-41.89
=72.88-41.89
=72.88-41.88-0.01
=30.99