(1)46.7-15.03-4.97
(2)1.25×2.5×0.8×40
(3)13÷2.5
(4)(
+
)×4+
.解:(1)46.7-15.03-4.97,=46.7-(15.03+4.97),
=46.7-20,
=26.7;
(2)1.25×2.5×0.8×40,
=1.25×0.8×2.5×40,
=(1.25×0.8)×(2.5×40),
=1×100,
=100;
(3)13÷2.5,
=(13×4)÷(2.5×4),
=52÷10,,
=5.2,
(4)(
+
)×4+
,=
×4+
×4+
,=
+
,=
+(
+
),=
+1,=1
.分析:(1)根据减法的性质简便计算;
(2)先运用乘法交换律,把1.25和0.8交换位置,再运用乘法结合律,(1.25×0.8)×(2.5×40)计算;
(3)根据商不变性质,把原式化成(13×4)÷(2.5×4)计算;
(4)先运用乘法分配律,(
+
)×4=
×4+
×4=
,再运用加法结合律(
+
)计算.点评:本题主要考查学生运用四则运算的简便方法计算的能力.