(2014•桐梓县模拟)计算下面各题,能简算的要简算:

1个回答

  • 解题思路:(1)先算加法,再算中括号里面的乘法,再算减法,最后算括号外面的乘法;

    (2)根据除法的性质进行简算;

    (3)根据乘法分配律进行简算;

    (4)根据乘法分配律进行简算;

    (5)按照从左向右的顺序进行计算;

    (6)先算加法,再算乘法,再算减法,最后算除法.

    (1)[800×(1+[1/4])-360]×2.5

    =[800×1[1/4]-360]×2.5

    =[1000-360]×2.5

    =640×2.5

    =1600;

    (2)7200÷25÷4

    =7200÷(25×4)

    =7200÷100

    =72;

    (3)46.5×43.5+4.35×285-25×43.5

    =46.5×43.5+43.5×28.5-25×43.5

    =(46.5+28.5-25)×43.5

    =50×43.5

    =2175;

    (4)5.25×[11/12]+[11/12]×[3/4]

    =(5.25+[3/4])×[11/12]

    =6×[11/12]

    =[11/2];

    (5)[5/6]×[1/15]÷[7/18]

    =[1/18]÷[7/18]

    =[1/7];

    (6)[3.75-(0.2+[1/3])×4.5]÷13.5

    =[3.75-[8/15]×4.5]÷13.5

    =[3.75-2.4]÷13.5

    =1.35÷13.5

    =0.1.

    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.

    考点点评: 考查了运算定律与简便运算,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简便计算.