48×( - ) | - - + | 632-486÷18+395 |
[ -( + )]÷ | 0.75×74+ ×25+75% | + + + + + . |
-
),=48×
-48×
,=12-8,
=4;
(2)
-
-
+
,=(
)-(
),=5-4,
=1;
(3)632-486÷18+395,
=632-27+395,
=605+395,
=1000;
(4)[
-(
+
)]÷
,=[
-
]
,=0
,=0;
(5)0.75×74+
×25+75%,=0.75×(74+25+1),
=0.75×100,
=75;
(6)
+
+
+
+
+
,=1-
+
+…+
,=1-
,=
.分析:(1)运用乘法分配律解答,
(2)运用加法交换律,以及减法简便运算解答,
(3)先算第二级运算,再算第一级运算解答,
(4)根据四则运算顺序解答,
(5)运用乘法分配律解答,
(6)化
=1-
,
=
…
=
,
解答.点评:本题主要考查学生对于四则运算顺序,以及四则运算简便算法的掌握.