题目内容
能简便的要简便计算:
÷[
×(1-
)]
(39×
+
×4)÷
8.5×3.7-7.5×3.7
0.125×
+
×8.25+12.5%
(
+
)×15-45÷49.
| 6 |
| 13 |
| 7 |
| 11 |
| 3 |
| 7 |
(39×
| 2 |
| 7 |
| 2 |
| 7 |
| 2 |
| 7 |
8.5×3.7-7.5×3.7
0.125×
| 3 |
| 4 |
| 1 |
| 8 |
(
| 1 |
| 15 |
| 3 |
| 49 |
考点:整数、分数、小数、百分数四则混合运算
专题:运算顺序及法则
分析:①
÷[
×(1-
)],先算小括号里面的减法,再算中括号里面的乘法,最后算除法;
②(39×
+
×4)÷
,运用乘法分配律简算;
③8.5×3.7-7.5×3.7,运用乘法分配律简算;
④0.125×
+
×8.25+12.5%,运用乘法分配律简算;
⑤(
+
)×15-45÷49.运用乘法分配律简算.
| 6 |
| 13 |
| 7 |
| 11 |
| 3 |
| 7 |
②(39×
| 2 |
| 7 |
| 2 |
| 7 |
| 2 |
| 7 |
③8.5×3.7-7.5×3.7,运用乘法分配律简算;
④0.125×
| 3 |
| 4 |
| 1 |
| 8 |
⑤(
| 1 |
| 15 |
| 3 |
| 49 |
解答:
解:①
÷[
×(1-
)]
=
÷[
×
]
=
÷
=
×
=1
;
②(39×
+
×4)÷
=(39+4)×
×
=43×1
=43;
③8.5×3.7-7.5×3.7
=(8.5-7.5)×3.7
=1×3.7
=3.7;
④0.125×
+
×8.25+12.5%
=0.125×0.75+0.125×8.25+0.125
=0.125×(0.75+8.25+1)
=0.125×10
=1.25;
⑤(
+
)×15-45÷49
=
×15+
×15-
=1+
-
=1.
| 6 |
| 13 |
| 7 |
| 11 |
| 3 |
| 7 |
=
| 6 |
| 13 |
| 7 |
| 11 |
| 4 |
| 7 |
=
| 6 |
| 13 |
| 4 |
| 11 |
=
| 6 |
| 13 |
| 11 |
| 4 |
=1
| 7 |
| 26 |
②(39×
| 2 |
| 7 |
| 2 |
| 7 |
| 2 |
| 7 |
=(39+4)×
| 2 |
| 7 |
| 7 |
| 2 |
=43×1
=43;
③8.5×3.7-7.5×3.7
=(8.5-7.5)×3.7
=1×3.7
=3.7;
④0.125×
| 3 |
| 4 |
| 1 |
| 8 |
=0.125×0.75+0.125×8.25+0.125
=0.125×(0.75+8.25+1)
=0.125×10
=1.25;
⑤(
| 1 |
| 15 |
| 3 |
| 49 |
=
| 1 |
| 15 |
| 3 |
| 49 |
| 45 |
| 49 |
=1+
| 45 |
| 49 |
| 45 |
| 49 |
=1.
点评:此题考查的目的是理解整数整数、小数、分数四则混合运算的顺序以及它们的计算法则,并且能够灵活选择简便方法进行计算.
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