6.25×7+2×
-
.4.75×1.36×0.375.÷


.解:(1)8.16-1.26÷0.3×1.5,=8.16-4.2×1.5,
=8.16-6.3,
=1.86;
(2)6.25×7+2×
-
,=6
×7+2×
-
,=6
×(7+2-1),=6
×8,=50;
(3)4.75×1.36×0.375÷
,=4.75×1.36×0.375÷4.75÷1.36÷0.375,
=(4.75÷4.75)×(1.36÷1.36)×(0.375÷0.375),
=1×1×1,
=1;
(4)
,=
-
+
-
+
-
+
-
+
-
,=
-
,=
;(5)
,=[
×
+
×
]÷2
,=[(
+
)×
]÷2
,=(1×
)÷2
,=
÷2
,=
.分析:(1)先算除法,再算乘法,最后算减法;
(2)运用乘法分配律简算;
(3)根据除法的性质简算;
(4)
=
-
,
=
-
,…由此化简求解;(5)先算小括号里面的减法,再把中括号里面的运算运用乘法分配律简算;最后算括号外的除法.
点评:此题是考查四则混合运算,要仔细观察算式的特点,灵活运用一些定律进行简便计算.