×2003 ②
×
+
÷3 ③36×
+17×0.25+47×25%④99×(1-
)×(1-
)×(1-
)×…×(1-
) ⑤
+
+
+
+
+
.解:①
×2003,=
×(2002+1),=
×2002+
×1,=2001+
,=2001
;②
×
+
÷3,=
×
+
×
,=(
+
)×
,=1×
,=
;③36×
+17×0.25+47×25%,=36×0.25+17×0.25+47×0.25,
=(36+17+47)×0.25,
=100×0.25,
=25;
④99×(1-
)×(1-
)×(1-
)×…×(1-
),=99×
×
×
×…×
,=99×
,=1;
⑤
+
+
+
+
+
,=1-
+
-
+
-
+
-
+
-
+
-
,=1-
,=
.分析:①把2003看作(2002+1),运用乘法分配律简算;
②把除法改为乘法,运用乘法分配律简算;
③把分数和百分数化为小数,运用乘法分配律简算;
④先算出括号内的结果,通过约分计算即可;
⑤通过观察,每个分数都可以分解成两个分数相减的形式,然后通过分数加减相互抵消,求得结果.
点评:完成此题,应仔细观察算式特点,运用运算定律或运算技巧,灵活解答.