问题 选择题
0.57×9.9的简便算法是(  )
A.0.57×10-0.57B.0.57×(10-1)
C.0.57×(10-0.1)
答案

0.57×9.9

=0.57×(10-1)

=0.57×10-0.57×0.1

=5.7-0.057

=5.643;

故选:C.

阅读理解与欣赏
单项选择题 A1/A2型题