题目内容
(2012?广东)计算下面各题,能简便计算的请简便计算.
(
+
)÷
+
6.5×0.64-6.5×0.54+6.5×90%
+
-
+
=
(
5 |
12 |
5 |
8 |
5 |
8 |
1 |
3 |
6.5×0.64-6.5×0.54+6.5×90%
4 |
7 |
1 |
5 |
3 |
7 |
4 |
5 |
分析:(1)先算括号内的,再算括号外的除法,最后算括号外的加法;
(2)运用乘法分配律简算;
(3)运用加法交换律与结合律简算.
(2)运用乘法分配律简算;
(3)运用加法交换律与结合律简算.
解答:解:(1)(
+
)÷
+
,
=
×
+
,
=
+
,
=2;
(2)6.5×0.64-6.5×0.54+6.5×90%,
=6.5×0.64-6.5×0.54+6.5×0.9,
=6.5×(0.64-0.54+0.9),
=6.5×1,
=6.5;
(3)
+
-
+
,
=(
-
)+(
+
),
=
+1,
=1
.
5 |
12 |
5 |
8 |
5 |
8 |
1 |
3 |
=
25 |
24 |
8 |
5 |
1 |
3 |
=
5 |
3 |
1 |
3 |
=2;
(2)6.5×0.64-6.5×0.54+6.5×90%,
=6.5×0.64-6.5×0.54+6.5×0.9,
=6.5×(0.64-0.54+0.9),
=6.5×1,
=6.5;
(3)
4 |
7 |
1 |
5 |
3 |
7 |
4 |
5 |
=(
4 |
7 |
3 |
7 |
1 |
5 |
4 |
5 |
=
1 |
7 |
=1
1 |
7 |
点评:此题小数、分数的四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算律简便计算.
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