解:(1)
÷(
-
)
=
÷
,
=
;
(2)
×[
-(
-
)]
=
×[
+
-
],
=
×[1-
],
=
×
,
=
;
(3)
÷[
×(
+
)]
=
÷[
×
],
=
×15,
=9
;
(4)
÷
+
×
=
×
+
×
,
=(
+
)×
,
=1×
,
=
;
(5)5.58-
+5.42-
=(5.58+5.42)-(
+
),
=11-1,
=10;
(6)999
+99
+9
+
.
=1000+100+10+
-
-
-
,
=1110+(
-
3),
=1110+(
-
).
=1110+0,
=1110.
分析:(1)(3)根據(jù)四則混合運(yùn)算的運(yùn)算順序計(jì)算即可:先算乘除,再算加減,有括號(hào)的要先算括號(hào)里面的;
(2)可根據(jù)一個(gè)數(shù)減去兩個(gè)數(shù)的差,等于用這個(gè)數(shù)減去兩個(gè)數(shù)中的被減數(shù),加上減數(shù)的減法性質(zhì)計(jì)算;
(4)可根據(jù)乘法分配律計(jì)算;
(5)可根據(jù)加法交換律及一個(gè)數(shù)減兩個(gè)數(shù),等于減去這兩個(gè)數(shù)的和的減法性質(zhì)計(jì)算;
(6)可用湊整法計(jì)算.
點(diǎn)評(píng):完成本題要細(xì)心分析式中數(shù)據(jù)的特點(diǎn)及內(nèi)在聯(lián)系,然后運(yùn)用合適的方法計(jì)算.