(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.