下面各题怎样简便就怎样算.(1)3.7×99+3.7 (2)[3/4]×7.7+3.3×0.75-75% (3)5.93
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解题思路:(1)(6)运用乘法分配律简算;(2)把分数和百分数化为小数,运用乘法分配律简算;(3)运用加法交换律与结合律简算;(4)先算括号内的除法,再算括号内的减法,最后算括号外的乘法;(5)运用除法的性质简算.

(1)3.7×99+3.7,

=3.7×(99+1),

=3.7×100,

=370;

(2)[3/4]×7.7+3.3×0.75-75%,

=0.75×7.7+3.3×0.75-0.75,

=0.75×(7.7+3.3-1),

=0.75×10,

=7.5;

(3)5.93+0.64+0.07+0.36,

=(5.93+0.07)+(0.64+0.36),

=6+1,

=7;

(4)(7.9-3.06÷0.68)×1.5,

=(7.9-4.5)×1.5,

=3.4×1.5,

=5.1;

(5)78÷2.5÷0.4,

=78÷(2.5×0.4),

=78÷1,

=78;

(6)105×([1/3]+[1/5]),

=105×[1/3]+105×[1/5],

=35+21,

=56.

点评:

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

考点点评: 完成本题要注意分析式中数据,运用合适的简便方法计算.