题目内容
(2010?苍南县)用简便方法计算,要写出简算过程
|
94×99 | (
|
10-
|
分析:(1)运用减法的性质简算;
(2)先把99分解成100-1,再运用乘法分配律简算;
(3)先算小括号里面的减法,再算括号外的除法,最后算加法;
(4)先算除法,再算减法,最后算加法.
(2)先把99分解成100-1,再运用乘法分配律简算;
(3)先算小括号里面的减法,再算括号外的除法,最后算加法;
(4)先算除法,再算减法,最后算加法.
解答:解:(1)
-(3.19+
),
=
-
-3.19,
=4-3.19,
=0.81;
(2)94×99,
=94×(100-1),
=94×100-94×1,
=9400-94,
=9306;
(3)(
-
)÷
+0.8,
=
÷
+0.8,
=
+0.8,
=2.05;
(4)10-
÷
+5.2,
=10-6+5.2,
=4+5.2,
=9.2.
31 |
7 |
3 |
7 |
=
31 |
7 |
3 |
7 |
=4-3.19,
=0.81;
(2)94×99,
=94×(100-1),
=94×100-94×1,
=9400-94,
=9306;
(3)(
4 |
5 |
3 |
4 |
1 |
25 |
=
1 |
20 |
1 |
25 |
=
5 |
4 |
=2.05;
(4)10-
9 |
13 |
3 |
26 |
=10-6+5.2,
=4+5.2,
=9.2.
点评:本题考查了四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律进行简便计算.
练习册系列答案
相关题目