题目内容
计算下面各题,能简便的要简便计算.
①
÷
+
×
;
②(
-
)×24+
;
③
÷
×
;
④
÷[(
-
)×
].
①
11 |
15 |
5 |
3 |
4 |
15 |
3 |
5 |
②(
5 |
6 |
7 |
12 |
1 |
3 |
③
5 |
8 |
7 |
16 |
14 |
25 |
④
4 |
5 |
3 |
4 |
1 |
6 |
4 |
7 |
分析:①把除法变为乘法,运用乘法分配律简算;
②算式(
-
)×24,运用乘法分配律简算,然后加上
即可;
③把除法变为乘法,约分计算;
④先算小括号内的,再算中括号内的,最后算括号外的.
②算式(
5 |
6 |
7 |
12 |
1 |
3 |
③把除法变为乘法,约分计算;
④先算小括号内的,再算中括号内的,最后算括号外的.
解答:解:①
÷
+
×
=
×
+
×
=(
+
)×
=1×
=
②(
-
)×24+
=
×24-
×24+
=20-14+
=6+
=6
③
÷
×
=
×
×
=
④
÷[(
-
)×
]
=
÷[
×
]
=
÷
=
×3
=
11 |
15 |
5 |
3 |
4 |
15 |
3 |
5 |
=
11 |
15 |
3 |
5 |
4 |
15 |
3 |
5 |
=(
11 |
15 |
4 |
15 |
3 |
5 |
=1×
3 |
5 |
=
3 |
5 |
②(
5 |
6 |
7 |
12 |
1 |
3 |
=
5 |
6 |
7 |
12 |
1 |
3 |
=20-14+
1 |
3 |
=6+
1 |
3 |
=6
1 |
3 |
③
5 |
8 |
7 |
16 |
14 |
25 |
=
5 |
8 |
16 |
7 |
14 |
25 |
=
4 |
5 |
④
4 |
5 |
3 |
4 |
1 |
6 |
4 |
7 |
=
4 |
5 |
7 |
12 |
4 |
7 |
=
4 |
5 |
1 |
3 |
=
4 |
5 |
=
12 |
5 |
点评:此题考查了分数的四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律简便计算.
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