
×13×30
×
+
×
+
×7.6+2.4×0.6解:(1)0.25×19+5×
=
×19+5×
,=
×(19+5),=
×24,=6;
(2)
×13×30=
×30×13,=4×13,
=52;
(3)
×
+
×
+
=
×
+
×
+
,=
×(
+
)+
,=
+
,=1;
(4)
×7.6+2.4×0.6.=0.6×7.6+2.4×0.6,
=0.6×(7.6+2.4),
=0.6×10,
=6.
分析:(1)(4)可根据乘法分配律计算;
(2)可根据乘法交换律计算;
(3)可将
×
=
×
后连续运用乘法分配律计算.点评:完成本题要注意分析式中数据的特点,然后运用合适的方法进行计算.