用你喜欢的方法计算. (1)4444/7×0.25 (2)27×3.4+15.4×34-340×81% (3)155×23/156+11/156×3 (4)1/2008+2/2008+3/2008+…+2007/2008.
问题描述:
用你喜欢的方法计算.
(1)444
×0.254 7
(2)27×3.4+15.4×34-340×81%
(3)155×
+23 156
×311 156
(4)
+1 2008
+2 2008
+…+3 2008
. 2007 2008
答
(1)444
×0.25,4 7
=444×0.25+
×0.25,4 7
=111+
,1 7
=111
;1 7
(2)27×3.4+15.4×34-340×81%,
=3.4×(27+154-81),
=3.4×100,
=340;
(3)155×
+23 156
×3,11 156
=156×
-1×23 156
+23 156
,33 156
=23+
,10 156
=23
;5 78
(4)
+1 2008
+2 2008
+…+3 2008
,2007 2008
=
+(1+2007)+(2+2006)+…(1003+1005) 2008
,1004 2008
=
+2008×1003 2008
,1 2
=1003+
,1 2
=1003
.1 2