题目内容
脱式计算
(1)0.36+0.63×2.8-1
(2)1.5×5
-
+0.35
(3)1
×[0.625+(4
-2
)÷(1.83+
)]
(4)7
÷
-(
+2
)×2
.
(1)0.36+0.63×2.8-1
1 |
3 |
(2)1.5×5
1 |
3 |
3 |
4 |
(3)1
5 |
52 |
1 |
6 |
4 |
15 |
9 |
20 |
(4)7
12 |
5 |
18 |
25 |
7 |
12 |
5 |
8 |
5 |
14 |
分析:(1)先算乘法,再算加法,最后算减法;
(2)先算乘法,再算减法,最后算加法;
(3)先分别计算两个小括号里面的减法和加法,再算中括号里面的除法,同时把繁分数化简,最后用乘法分配律简算;
(4)先用乘法分配律简算,再算括号外的除法,最后算减法.
(2)先算乘法,再算减法,最后算加法;
(3)先分别计算两个小括号里面的减法和加法,再算中括号里面的除法,同时把繁分数化简,最后用乘法分配律简算;
(4)先用乘法分配律简算,再算括号外的除法,最后算减法.
解答:解:(1)0.36+0.63×2.8-1
,
=0.36+1.764-1
,
=2.124-1
,
=
;
(2)1.5×5
-
+0.35,
=8-
+0.35,
=7.25+0.35,
=7.6;
(3)1
×[0.625+(4
-2
)÷(1.83+
)],
=1
×[0.625+1.9÷2.28],
=1
×[0.625+
],
=
×
+
×
,
=
+1,
=1
;
(4)7
÷
-(
+2
)×2
,
=7
÷
-(
×
+
×
),
=7
÷
-(
+
),
=7
÷
-
,
=
-
,
=
.
1 |
3 |
=0.36+1.764-1
1 |
3 |
=2.124-1
1 |
3 |
=
593 |
750 |
(2)1.5×5
1 |
3 |
3 |
4 |
=8-
3 |
4 |
=7.25+0.35,
=7.6;
(3)1
5 |
52 |
1 |
6 |
4 |
15 |
9 |
20 |
=1
5 |
52 |
=1
1 |
5 |
5 |
6 |
=
6 |
5 |
5 |
8 |
6 |
5 |
5 |
6 |
=
3 |
4 |
=1
3 |
4 |
(4)7
12 |
5 |
18 |
25 |
7 |
12 |
5 |
8 |
5 |
14 |
=7
12 |
5 |
18 |
25 |
7 |
12 |
33 |
14 |
21 |
8 |
33 |
14 |
=7
12 |
5 |
18 |
25 |
11 |
8 |
99 |
16 |
=7
12 |
5 |
18 |
25 |
121 |
16 |
=
235 |
18 |
121 |
16 |
=
791 |
144 |
点评:此题主要考查分数、整数、小数的四则混合运算的运算顺序和应用运算定律进行简便计算.
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