解:(1)0.8×6.5-
×3.5,
=0.8×6.5-0.8×3.5,
=(6.5-3.5)×0.8,
=3×0.8,
=2.4;
(2)(
+
)×45,
=
×45+
×45,
=3+35,
=38;
(3)1-
÷
+
,
=1-
×
+
,
=1-
+
,
=1;
(4)25×1.25×32,
=25×1.25×8×4,
=25×4×(1.25×8),
=100×10,
=1000;
(5)99×
+
,
=(99+1)×
,
=100×
,
=90;
(6)1
-
-
,
=1
-(
+
),
=1
-1,
=
.
分析:(1)把分?jǐn)?shù)化為小數(shù),運(yùn)用乘法分配律的逆運(yùn)算簡算;
(2)根據(jù)數(shù)字特點(diǎn),運(yùn)用乘法分配律簡算;
(3)先算
÷
=
,與后面的
抵消;
(4)根據(jù)題目特點(diǎn),把32拆成8×4,再運(yùn)用乘法交換律和結(jié)合律簡算;
(5)把
看作1×
,運(yùn)用乘法分配律的逆運(yùn)算簡算;
(6)運(yùn)用減法的性質(zhì)把原式變?yōu)?
-(
+
),括號內(nèi)的結(jié)果為1,然后相減即可.
點(diǎn)評:解答此類問題應(yīng)注意審題,認(rèn)真分析數(shù)據(jù),抓住數(shù)字特點(diǎn),運(yùn)用合適的簡便方法計算.