题目内容
能简算的用简便方法计算.
(1)
×
-
÷
(2)
÷[(
+
)×2]
(3)
×99+
.
(1)
7 |
2 |
5 |
8 |
3 |
2 |
8 |
5 |
(2)
4 |
5 |
3 |
5 |
1 |
2 |
(3)
8 |
25 |
8 |
25 |
考点:分数的简便计算,分数的四则混合运算
专题:运算顺序及法则,运算定律及简算
分析:(1)根据乘法分配律进行简算;
(2)先算加法,再算乘法,最后算除法;
(3)根据乘法分配律进行简算.
(2)先算加法,再算乘法,最后算除法;
(3)根据乘法分配律进行简算.
解答:
解:(1)
×
-
÷
=
×
-
×
=(
-
)×
=2×
=
;
(2)
÷[(
+
)×2]
=
÷[
×2]
=
÷
=
;
(3)
×99+
=
×(99+1)
=
×100
=32.
7 |
2 |
5 |
8 |
3 |
2 |
8 |
5 |
=
7 |
2 |
5 |
8 |
3 |
2 |
5 |
8 |
=(
7 |
2 |
3 |
2 |
5 |
8 |
=2×
5 |
8 |
=
5 |
4 |
(2)
4 |
5 |
3 |
5 |
1 |
2 |
=
4 |
5 |
11 |
10 |
=
4 |
5 |
11 |
5 |
=
4 |
11 |
(3)
8 |
25 |
8 |
25 |
=
8 |
25 |
=
8 |
25 |
=32.
点评:考查了运算定律与简便运算,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.
练习册系列答案
相关题目
把3.29的小数点去掉,这个数比原数大( )
A、325.71 | B、0.29 |
C、329 | D、325 |