简便计算125×64-24×64-64???????????????19+21+23+…+49+51(25+19)×4?????????????????????999

发布时间:2020-07-30 18:38:44

简便计算
125×64-24×64-64???????????????19+21+23+…+49+51(25+19)×4?????????????????????99999×26+33333×2225×125×32????????????????????????????102×889000÷25÷4????????????????????????????99×46.

网友回答

解:(1)125×64-24×64-64,
=(125-24-1)×64,
=100×64,
=6400;

(2)19+21+23+…+49+51,
=(19+51)+(21+49)+…(33+37)+35,
=70×8+35,
=560+35,
=595;

(3)(25+19)×4,
=25×4+19×4,
=100+76,
=176;

(4)99999×26+33333×22,
=33333×78+33333×22,
=33333×(78+22),
=33333×100,
=3333300;

(5)25×125×32,
=(25×4)×(125×8),
=100×1000,
=100000;

(6)102×88,
=100×88+2×88,
=8800+176,
=8976;

(7)9000÷25÷4,
=9000÷(25×4),
=9000÷100,
=90;

(8)99×46.
=100×46-46,
=4600-46,
=4554.

解析分析:(1)125×64-24×64-64,运用乘法分配律进行简算;(2)19+21+23+…+49+51,运用加法交换律和结合律进行简算;(3)(25+19)×4,运用乘法分配律进行简算;(4)99999×26+33333×22,根据积的变化规律转化为:33333×78+33333×22,运用乘法分配律进行简算;(5)25×125×32,运用乘法分配律进行简算;(6)102×88运用乘法分配律进行简算;(7)9000÷25÷4,根据除法的运算性质进行简算;(8)99×46.运用乘法分配律进行简算.

点评:此题考查的目的是使学生运用加法、乘法的运算定律和运算性质进行简便计算.
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