问题
解答题
用简便方法计算下面各题. (1)
(2)2011×
|
答案
(1)
×41,54 55
=(1-
)×41,1 55
=1×41-
×41,1 55
=41-
,41 55
=40
;14 55
(2)2011×
,19 2010
=(2010+1)×
,19 2010
=2010×
+1×19 2010
,19 2010
=19+
,19 2010
=19
.19 2010