考點(diǎn):小數(shù)四則混合運(yùn)算,整數(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
分析:(1)(7)(8)(10)運(yùn)用加法交換律與結(jié)合律簡算;
(2)運(yùn)用加法結(jié)合律簡算;
(3)先算括號內(nèi)的,原式變?yōu)?8×125,再把18拆成10+8,運(yùn)用乘法分配律簡算;
(4)把102看作100+2,運(yùn)用乘法分配律簡算;
(5)把32看作8×4,運(yùn)用乘法結(jié)合律簡算;
(6)(9)運(yùn)用乘法分配律簡算.
解答:
解:(1)11.1+1.11+8.9+0.89
=(11.1+8.9)+(1.11+0.89)
=20+2
=22
(2)973+273-73
=973+(273-73)
=973+200
=1173
(3)﹙67-49﹚×125
=18×125
=(10+8)×125
=10×125+8×125
=1250+1000
=2250
(4)38×102
=38×(100+2)
=38×100+2×38
=3800+76
=3876
(5)125×32×25
=(125×8)×(4×25)
=1000×100
=100000
(6)186×59-59×86
=(186-86)×59
=100×59
=5900
(7)8.62-4.95-0.62
=(8.62-0.62)-4.95
=8-4.95
=3.05
(8)28.75+﹙1.32-0.75﹚
=(28.75-0.75)+1.32
=28+1.32
=29.32
(9)0.25×75+0.25×25
=0.25×(75+25)
=0.25×100
=25
(10)6.81+1.6+3.19+0.4
=(6.81+3.19)+(1.6+0.4)
=10+2
=12
點(diǎn)評:完成本題要注意分析式中數(shù)據(jù),運(yùn)用合適的簡便方法計(jì)算.