1.68+68×31+68×69+68×99 2.47×520+530×52,怎样简便计算?

问题描述:

1.68+68×31+68×69+68×99 2.47×520+530×52,怎样简便计算?

1.68+68×31+68×69+68×99
=68×(1+31+69+99)
=69×200
=13800
2.47×520+530×52
=470×52+530×52
=1000×52
=52000