题目内容
（1）
÷[（
+
）×
]
（2）[
÷（
+
）-
]×
（3）51.2×8.1+11×9.25+637×0.19
（4）（2
+1
×5）÷3
+342
×
．
| 8 |
| 9 |
| 2 |
| 5 |
| 1 |
| 10 |
| 3 |
| 4 |
（2）[
| 3 |
| 4 |
| 4 |
| 5 |
| 1 |
| 4 |
| 4 |
| 7 |
| 9 |
| 11 |
（3）51.2×8.1+11×9.25+637×0.19
（4）（2
| 2 |
| 5 |
| 1 |
| 3 |
| 2 |
| 5 |
| 3 |
| 7 |
| 7 |
| 9 |
（1）
| 8 |
| 9 |
| 2 |
| 5 |
| 1 |
| 10 |
| 3 |
| 4 |
=
| 8 |
| 9 |
| 1 |
| 2 |
| 3 |
| 4 |
=
| 8 |
| 9 |
| 3 |
| 8 |
=
| 64 |
| 27 |
（2）[
| 3 |
| 4 |
| 4 |
| 5 |
| 1 |
| 4 |
| 4 |
| 7 |
| 9 |
| 11 |
=[
| 3 |
| 4 |
| 21 |
| 20 |
| 4 |
| 7 |
| 9 |
| 11 |
=[
| 5 |
| 7 |
| 4 |
| 7 |
| 9 |
| 11 |
=
| 1 |
| 7 |
| 9 |
| 11 |
=
| 9 |
| 77 |
（3）51.2×8.1+11×9.25+637×0.19，
=512×0.81+637×0.19+11×9.25，
=512×（1-0.19）+637×0.19+（10+1）×9.25，
=512×1-512×0.19+637×0.19+10×9.25+1×9.25，
=512+0.19×（637-512）+92.5+9.25，
=512+0.19×125+92.5+9.25，
=512+92.5+9.25+（0.2-0.01）×125，
=512+92.5+9.25+0.2×125-0.01×125，
=512+92.5+9.25+25-1.25，
=（512+25）+（9.25-1.25）+92.5，
=537+8+92.5，
=545+92.5，
=637.5；
（4）（2
| 2 |
| 5 |
| 1 |
| 3 |
| 2 |
| 5 |
| 3 |
| 7 |
| 7 |
| 9 |
=（2
| 2 |
| 5 |
| 2 |
| 3 |
| 2 |
| 5 |
| 1 |
| 3 |
=9
| 1 |
| 15 |
| 2 |
| 5 |
| 1 |
| 3 |
=2
| 2 |
| 3 |
| 1 |
| 3 |
=269．
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