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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