简便计算125×64-24×64-64

1个回答

  • 解题思路:(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.

    (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.

    点评:

    本题考点: 运算定律与简便运算.

    考点点评: 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.