题目内容
(2013?海安县)怎样算简便就怎样算.
| 337-298 | 0.8-0.2×1.9÷7.6 |
| ||||||||||||
|
(4.9-3.9÷3)×
|
4×3×(
|
分析:(1)可根据凑整法计算;
(2)(5)根据四则混合运算的运算顺序计算即可:先算乘除,再算加减,有括号的要先算括号里面的;
(3)(6)根据乘法分配律计算即可;
(4)可根据一个数减两个数的差等于用这个数减去两个数中的被减数加上减数的减法性质及加法交换律律计算.
(2)(5)根据四则混合运算的运算顺序计算即可:先算乘除,再算加减,有括号的要先算括号里面的;
(3)(6)根据乘法分配律计算即可;
(4)可根据一个数减两个数的差等于用这个数减去两个数中的被减数加上减数的减法性质及加法交换律律计算.
解答:解:(1)337-298
=337-300+2,
=37+2,
=39;
(2)0.8-0.2×1.9÷7.6
=0.8-0.38÷7.6.
=0.8-0.05,
=0.75;
(3)
÷8+
×
=
×
+
×
,
=(
+
)×
,
=
×
,
=
;
(4)
-(
-
)
=
+
-
,
=1-
,
=
;
(5)(4.9-3.9÷3)×
=(4.9-1.3)×
,
=3.6×
,
=1.2;
(6)4×3×(
+
)
=12×
+12×
,
=9+8,
=17.
=337-300+2,
=37+2,
=39;
(2)0.8-0.2×1.9÷7.6
=0.8-0.38÷7.6.
=0.8-0.05,
=0.75;
(3)
| 7 |
| 13 |
| 1 |
| 8 |
| 5 |
| 13 |
=
| 7 |
| 13 |
| 1 |
| 8 |
| 1 |
| 8 |
| 5 |
| 13 |
=(
| 7 |
| 13 |
| 5 |
| 13 |
| 1 |
| 8 |
=
| 12 |
| 13 |
| 1 |
| 8 |
=
| 3 |
| 26 |
(4)
| 6 |
| 7 |
| 4 |
| 5 |
| 1 |
| 7 |
=
| 6 |
| 7 |
| 1 |
| 7 |
| 4 |
| 5 |
=1-
| 4 |
| 5 |
=
| 1 |
| 5 |
(5)(4.9-3.9÷3)×
| 1 |
| 3 |
=(4.9-1.3)×
| 1 |
| 3 |
=3.6×
| 1 |
| 3 |
=1.2;
(6)4×3×(
| 3 |
| 4 |
| 2 |
| 3 |
=12×
| 3 |
| 4 |
| 2 |
| 3 |
=9+8,
=17.
点评:完成此类题目要注意分析式中数据的特点及内在联系,然后运用合适的方法计算.
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