题目内容
看谁算得快．
+
=
+
=
+
-
=
1-
-
=
+
=
-
=
+
+
=
+
-
=
| 1 |
| 2 |
| 1 |
| 4 |
| 1 |
| 3 |
| 1 |
| 5 |
| 7 |
| 9 |
| 1 |
| 3 |
| 7 |
| 9 |
1-
| 7 |
| 12 |
| 5 |
| 12 |
| 1 |
| 7 |
| 6 |
| 7 |
| 1 |
| 3 |
| 1 |
| 5 |
| 1 |
| 4 |
| 1 |
| 7 |
| 3 |
| 4 |
| 9 |
| 8 |
| 1 |
| 9 |
| 9 |
| 8 |
分析：根据分数加减法的计算方法进行计算；
1-
-
根据连减的性质进行计算；
+
-
、
+
+
和
+
-
根据加法交换律进行计算．
1-
| 7 |
| 12 |
| 5 |
| 12 |
| 7 |
| 9 |
| 1 |
| 3 |
| 7 |
| 9 |
| 1 |
| 4 |
| 1 |
| 7 |
| 3 |
| 4 |
| 9 |
| 8 |
| 1 |
| 9 |
| 9 |
| 8 |
解答：解：
+
=
，
+
=
，
+
-
=
，
1-
-
=0，
+
=1，
-
=
，
+
+
=1
，
+
-
=
．
| 1 |
| 2 |
| 1 |
| 4 |
| 3 |
| 4 |
| 1 |
| 3 |
| 1 |
| 5 |
| 8 |
| 15 |
| 7 |
| 9 |
| 1 |
| 3 |
| 7 |
| 9 |
| 1 |
| 3 |
1-
| 7 |
| 12 |
| 5 |
| 12 |
| 1 |
| 7 |
| 6 |
| 7 |
| 1 |
| 3 |
| 1 |
| 5 |
| 2 |
| 15 |
| 1 |
| 4 |
| 1 |
| 7 |
| 3 |
| 4 |
| 1 |
| 7 |
| 9 |
| 8 |
| 1 |
| 9 |
| 9 |
| 8 |
| 1 |
| 9 |
点评：口算时，注意运算符号和数据，然后再进一步计算．
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