递等式计算(能简便的要用简便方法计算).

1个回答

  • 解题思路:(1)算出括号里面的得数后,化3.2=4×0.8解答,

    (2)先算出(3.8+0.2)=4,再运用乘法交换律解答,

    (3)依据四则运算计算方法解答,

    (4)化0.375×8=3.75×0.8,运用乘法分配律解答.

    (1)(1÷0.5+0.5÷1)×3.2,

    =(2+0.5)×3.2,

    =2.5×4×0.8,

    =10×0.8,

    =8;

    (2)0.25×3.7×(3.8+0.2),

    =0.25×4×3.7,

    =1×3.7,

    =3.7;

    (3)52.8÷[18.2-(4.24÷0.8-0.3)],

    =52.8÷[18.2-(5.3-0.3)],

    =52.8÷[18.2-5],

    =52.8÷13.2,

    =4;

    (4)0.375×8-0.8+7.25×0.8,

    =0.8×(3.75-1+7.25),

    =0.8×10,

    =8.

    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: 本题主要考查学生对于四则运算计算方法,以及四则运算简便算法的掌握.