用递等式计算. ①1.08×0.8÷0.27 ②9.07-22.78÷3.4 ③20.88÷0.8-12.9+1.1 ④

1个回答

  • 解题思路:①按照从左到右的顺序计算;

    ②先算除法,再算减法;

    ③先算除法,再算减法,最后算加法;

    ④先把4.4分解成4×1.1,再运用乘法结合律简算,最后算加法.

    ①1.08×0.8÷0.27,

    =0.864÷0.27,

    =3.2;

    ②9.07-22.78÷3.4,

    =9.07-6.7,

    =2.37;

    ③20.88÷0.8-12.9+1.1,

    =26.1-12.9+1.1,

    =13.2+1.1,

    =14.2;

    ④0.75+0.25×4.4,

    =0.75+0.25×4×1.1,

    =0.75+1×1.1,

    =0.75+1.1,

    =1.85.

    点评:

    本题考点: 小数四则混合运算.

    考点点评: 本题考查了简单的四则混合运算,关键是理清楚运算的顺序,然后根据运算顺序逐步求解即可.