285+195+105+415
643-48-12-40
25×32
8×48×125
5400÷45÷2
360÷45
148×8+152×8
99×34
25×201-25.
解:(1)285+195+105+415,
=(285+415)+(195+105),
=700+300,
=1000;
(2)643-48-12-40,
=643-(48+12+40),
=643-100,
=543;
(3)25×32,
=(25×4)×8,
=100×8,
=800;
(4)8×48×125,
=(8×125)×48,
=1000×48,
=48000;
(5)5400÷45÷2,
=5400÷(45×2),
=5400÷90,
=60;
(6)360÷45,
=360÷9÷5,
=40÷5,
=8;
(7)148×8+152×8,
=(148+152)×8,
=300×8,
=2400;
(8)99×34,
=34×100-34×1,
=3400-34,
=3366;
(9)25×201-25,
=25×(201-1),
=25×200,
=5000.
分析:(1)运用加法交换律和结合律解答;
(2)依据减法性质解答;
(3)化32=4×8,再运用乘法结合律即可解答;
(4)运用乘法交换律解答;
(5)依据除法性质即可解答;
(6)化45=9×5,再运用除法性质即可解答;
(7)(8)(9)运用乘法分配律解答.
点评:本题主要考查学生正确运用简便算法解决问题的能力.