题目内容
(2011?黔南州)用简便方法计算.
×4+
×2
(
-
+
)×12
0.125×25×32.
5 |
6 |
5 |
6 |
(
1 |
3 |
1 |
6 |
1 |
4 |
0.125×25×32.
分析:(1)、(2)运用乘法分配律简算;(3)先把32分解成4×8,再运用乘法结合律简算.
解答:解:(1)
×4+
×2,
=
×(4+2),
=
×6,
=5;
(2)(
-
+
)×12,
=
×12-
×12+
×12,
=4-2+3,
=5;
(3)0.125×25×32,
=0.125×25×4×8,
=(0.125×8)×(25×4),
=1×100,
=100.
5 |
6 |
5 |
6 |
=
5 |
6 |
=
5 |
6 |
=5;
(2)(
1 |
3 |
1 |
6 |
1 |
4 |
=
1 |
3 |
1 |
6 |
1 |
4 |
=4-2+3,
=5;
(3)0.125×25×32,
=0.125×25×4×8,
=(0.125×8)×(25×4),
=1×100,
=100.
点评:运算定律是常用的简便运算的方法,要熟练掌握,灵活运用.
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