考點(diǎn):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)利用減法的性質(zhì)簡算;
(2)先算減法,再算除法,最后算乘法;
(3)把32=8×4,利用結(jié)合律簡算;
(4)(9)利用乘法分配律簡算;
(5)利用加法交換律與結(jié)合律簡算;
(6)先算除法,再算減法;
(7)利用除法的性質(zhì)簡算;
(8)先算除法,再算減法,最后算加法.
解答:
解:(1)168-52-48
=168-(52+48)
=168-100=
=68;
(2)(841-41)÷25×4
=800÷25×4
=32×4
=128;
(3)125×32×25
=(125×8)×(25×4)
=1000×100
=100000;
(4)101×87
=100×87+87
=8700+87
=8787;
(5)37+256+63+44
=(37+63)+(256+44)
=100+300
=400;
(6)235-135÷5
=235-27
=208;
(7)13000÷125÷8
=13000÷(125×8)
=13000÷1000
=13;
(8)160+(406-438÷73)
=160+(406-6)
=160+400
=560;
(9)83×29+72×83-83
=83×(29+72-1)
=83×100
=8300.
點(diǎn)評: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.