计算,能简算的要简算. 3.25×0.45+6.75×0.45    7.5×102       5.64÷0.125÷

1个回答

  • 解题思路:(1)(6)运用乘法分配律简算;

    (2)把102看作100+2,运用乘法分配律简算;

    (3)运用除法的性质简算;

    (4)(5)按运算顺序从左往右依次运算.

    (1)3.25×0.45+6.75×0.45,

    =(3.25+6.75)×0.45,

    =10×0.45,

    =4.5;

    (2)7.5×102,

    =7.5×(100+2),

    =750+15,

    =765;

    (3)5.64÷0.125÷8,

    =5.64÷(0.125×8),

    =5.64÷1,

    =5.64;

    (4)26.9×0.48÷2.69,

    =26.9÷2.69×0.48,

    =1×0.48,

    =0.48;

    (5)5.4×2.5×0.7,

    =13.5×0.7,

    =9.45;

    (6)39.5×99+39.5,

    =39.5×(99+1),

    =39.5×100,

    =3950.

    点评:

    本题考点: 小数四则混合运算;运算定律与简便运算.

    考点点评: 此题考查了小数的四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律进行简便计算.