| 4.38-1.56+0.62-0.44 | 1375+450÷18×25 | 18-( + )×105 | 36×0.25+65× -1÷4. |
(1)4.38-1.56+0.62-0.44,
=(4.38+0.62)-(1.56+0.44),
=5-2,
=3;
(2)1375+450÷18×25,
=1375+25×25,
=1375+625,
=2000;
(3)18-(
+
)×105,=18-(
×105+
×105),=18-(7+5),
=18-12,
=6;
(4)36×0.25+65×
-1÷4,=36×0.25+65×0.25-1×0.25,
=(36+65-1)×0.25,
=100×0.25,
=25.
分析:(1)根据加法交换律和结合律以及减法的性质进行简算;
(2)先算除法,再算乘法,最后算加法;
(3)根据乘法分配律进行简算;
(4)根据乘法分配律进行简算.
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律简便计算.