(2012•彭州市模拟)神机妙算细又巧!(能简算的要写出简算过程)

1个回答

  • 解题思路:①用乘法结合律简算,其余题目用乘法分配律简算解答即可.

    ①4×0.8×2.5×12.5,

    =(4×2.5)×(0.8×12.5),

    =10×10,

    =100;

    ②2.3×85+2.3×15,

    =2.3×(85+15),

    =2.3×100,

    =230;

    ③36.5×99+36.5,

    =36.5×(99+1),

    =36.5×100,

    =3650;

    ④0.65×14+87×65%-[13/20],

    =0.65×(14+87-1),

    =0.65×100,

    =65;

    ⑤([2/3]-[1/2]+[1/6])÷[1/24],

    =([2/3]-[1/2]+[1/6])×24,

    =[2/3]×24-[1/2]×24+

    1

    6×24,

    =16-12+4,

    =8.

    点评:

    本题考点: 整数、分数、小数、百分数四则混合运算;运算定律与简便运算;分数的简便计算.

    考点点评: 本题是利用运算定律进行简算,记住运算定律,并灵活运用.