分析:算式①可將式子根據(jù)加法結(jié)合律和交換律變?yōu)椋?58+42)+(36+264)進行計算;
算式②可根據(jù)乘法分配律進行計算;
算式③可將式子根據(jù)減法性質(zhì)進行計算;
算式④可將99拆分為100-1后再根據(jù)乘法分配律計算;
算式⑤根據(jù)除法的性質(zhì)計算;
算式⑥先根據(jù)乘法分配律變?yōu)椋?25×(99+1),再根據(jù)乘法的結(jié)合律變?yōu)椋?2500×8×2計算即可.
解答:解:①158+36+42+264,
=(158+42)+(36+264),
=200+200,
=400;
②19×27+190×5+19×23,
=19×(27+50+23),
=19×100,
=1900;
③957-(158+457),
=957-457-158,
=500-158,
=342;
④301×99,
=301×(100-1),
=301×100-301,
=30100-300-1,
=29799;
⑤600÷12÷5,
=600÷(12×5),
=600÷60,
=10;
⑥(125×99+125)×16
=125×(99+1)×16,
=12500×8×2,
=100000×2,
=200000.
點評:本題考查了運算定律與簡便運算,四則混合運算.注意運根據(jù)數(shù)據(jù)的特點,靈活運用所學(xué)的運算定律進行簡便計算.