考點(diǎn):整數(shù)四則混合運(yùn)算,運(yùn)算定律與簡便運(yùn)算,小數(shù)四則混合運(yùn)算,整數(shù)、分?jǐn)?shù)、小數(shù)、百分?jǐn)?shù)四則混合運(yùn)算
專題:運(yùn)算順序及法則,運(yùn)算定律及簡算
分析:(1)先算除法,再算乘法,最后算減法;
(2)(3)先算乘法,再算減法,最后算除法;
(4)利用加法交換律與減法的性質(zhì)簡算;
(5)利用乘法分配律簡算;
(6)先算乘法和除法,再算加法.
解答:
解:(1)4034-34÷17×105
=4034-2×105
=4034-210
=3824;
(2)(5.68-1.25×4)÷3.4
=(5.68-5)÷3.4
=0.68÷3.4
=0.2;
(3)(
-
×
)÷
=(
-
)÷
=
×
=
;
(4)7.98-
-
+2.12
=(7.98+2.12)-(
+
)
=10-1
=9;
(5)
×101
=
×100+
×1
=97+
=97
;
(6)
×
+
÷
=
+
×
=
+
=
.
點(diǎn)評:整數(shù)混合運(yùn)算的關(guān)鍵是抓住運(yùn)算順序,正確按運(yùn)算順序計(jì)算,適當(dāng)利用運(yùn)算定律簡算.