解;(1)9.47-(1.47+0.76),
=9.47-1.47-0.76,
=8-0.76,
=7.24;
(2)23-
÷
×
,
=23-
×
×
,
=23-
,
=
;
(3)1
-(
-
),
=1
-
+
,
=1
;
(4)(
+
)÷
,
=(
+
)×
,
=
×
+
×
,
=6+1,
=7;
(5)
÷
+
÷
,
=
×
+
×
,
=(
+
)×
,
=7×
,
=25;
(6)67.5×2.4+3.25×24,
=6.75×24+3.25×24,
=(6.75+3.25)×24,
=10×24,
=240.
分析:(1)9.47-(1.47+0.76)去掉括號(hào),變成9.47-1.47-0.76計(jì)算簡(jiǎn)便;
(2)23-
÷
×
,先算
÷
×
,再算減;
(3)1
-(
-
)去掉括號(hào),變成1
-
+
計(jì)算簡(jiǎn)便;
(4)把除以
變成乘以
,再利用乘法的分配律計(jì)算;
(5)把
÷
變成
×
,
÷
變成
×
,再利用乘法的分配律計(jì)算;
(6)67.5×2.4+3.25×24,把67.5×2.4變成6.75×24,再利用乘法的分配律計(jì)算.
點(diǎn)評(píng):考查了運(yùn)算定律與簡(jiǎn)便運(yùn)算,四則混合運(yùn)算.注意運(yùn)算順序和運(yùn)算法則,靈活運(yùn)用所學(xué)的運(yùn)算律簡(jiǎn)便計(jì)算.