0.625×0.5+
+
×62.5% 2.5×(
+
+
+
)(111+999)÷[56×(
-
)]49.5×
-(50-
)×0.6.解:(1)0.625×0.5+
+
×62.5%,=0.625×0.5+0.625+0.5×0.625,
=(0.5+1+0.5)×0.625,
=2×0.625,
=1.25;
(2)2.5×(
+
+
+
),=2.5×(4×
),=2.5×4×
,=10×
,=9;
(3)(111+999)÷[56×(
-
)],=1110÷[56×
-56×
],=1110÷[24-21],
=1110÷3,
=370;
(4)49.5×
-(50-
)×0.6,=49.5×(10+0.6)-49.5×0.6,
=49.5×10+49.6×0.6-49.5×0.6,
=495+(0.6-0.6)×49.5,
=495+0×49.5,
=495+0,
=495.
分析:(1)(3)(4)可根据乘法分配律计算;
(2)可根据乘法的意义将加法算式变为乘法算式计算;
点评:当算式中同时含有小数,分数或百分数时,要根据式中数据的特点灵活将它们互化后再进行计算.