考點(diǎn):整數(shù)、分?jǐn)?shù)、小數(shù)、百分?jǐn)?shù)四則混合運(yùn)算,運(yùn)算定律與簡便運(yùn)算
專題:運(yùn)算順序及法則,運(yùn)算定律及簡算
分析:(1)先算除法和乘法,再算減法;
(2)先算除法和乘法,再算加法;
(3)根據(jù)除法的性質(zhì)以及乘法交換律和結(jié)合律進(jìn)行簡算;
(4)根據(jù)乘法交換律和結(jié)合律進(jìn)行簡算;
(5)先算加法,再算乘法,最后算減法;
(6)根據(jù)乘法分配律進(jìn)行簡算.
解答:
解:(1)3.12÷1.2-1.2×0.6
=2.6-0.72
=1.88;
(2)3000÷24+103×32
=125+3296
=3421;
(3)55×66÷(11×11)
=55×66÷11÷11
=(55÷11)×(66÷11)
=5×6
=30;
(4)
×12.5×
×8
=(
×
)×(12.5×8)
=
×100
=330;
(5)
-(
+
)×
=
-
×
=
-
=
;
(6)123×5.67+8.77×567
=123×5.67+877×5.67
=(123+877)×5.67
=1000×5.67
=5670.
點(diǎn)評(píng):考查了運(yùn)算定律與簡便運(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)算定律簡便計(jì)算.