题目内容
计算题(1)-54×2
1 |
4 |
1 |
2 |
2 |
9 |
1 |
2 |
5 |
9 |
7 |
12 |
(3)-4×7-(-3)×6+5; (4)-1-〔1-(1-0.5×
1 |
3 |
(5)-22-(-3)3×(-1)4-(-1)5; (6)(-
5 |
8 |
(7)(-1)+(-1)2+(-1)3+…+(-1)99+(-1)100;
(8)
1 |
5×9 |
1 |
9×13 |
1 |
13×17 |
1 |
101×105 |
分析:(1)将除法转化为乘法,约分化简计算即可;
(2)根据乘法分配律计算即可;
(3)先算乘法,再算加减法;
(4)去括号时根据乘法分配律计算;
(5)(6)先算乘方,再算乘法,再算加减法;
(7)相邻两个数的和为0;
(8)将式子变形为
×(
-
)+
×(
-
)+
×(
-
)+…+
×(
-
),两两抵消进行计算.
(2)根据乘法分配律计算即可;
(3)先算乘法,再算加减法;
(4)去括号时根据乘法分配律计算;
(5)(6)先算乘方,再算乘法,再算加减法;
(7)相邻两个数的和为0;
(8)将式子变形为
1 |
4 |
1 |
5 |
1 |
9 |
1 |
4 |
1 |
9 |
1 |
13 |
1 |
4 |
1 |
13 |
1 |
17 |
1 |
4 |
1 |
101 |
1 |
105 |
解答:解:(1)-54×2
÷(-4
)×
=54×
×
×
=6;
(2)(
-
+
)×(-36)
=-18+20-21
=-19;
(3)-4×7-(-3)×6+5
=-28+18+5
=-5;
(4)-1-[1-(1-0.5×
)]×6
=-1-[1-(1-
×
)]×6
=-1-6+6-
×
×6
=-1-6+6-1
=-2;
(5)-22-(-3)3×(-1)4-(-1)5
=-4+27×1+1
=-4+27+1
=24;
(6)(-
)×(-4)2-0.25×(-5)×(-4)3
=-
×16-0.25×5×64
=-10-80
=-90;
(7)(-1)+(-1)2+(-1)3+…+(-1)99+(-1)100
=-1+1-1+…-1+1
=0;
(8)
+
+
+…+
=
×(
-
)+
×(
-
)+
×(
-
)+…+
×(
-
)
=
×(
-
)
=
.
1 |
4 |
1 |
2 |
2 |
9 |
=54×
9 |
4 |
2 |
9 |
2 |
9 |
=6;
(2)(
1 |
2 |
5 |
9 |
7 |
12 |
=-18+20-21
=-19;
(3)-4×7-(-3)×6+5
=-28+18+5
=-5;
(4)-1-[1-(1-0.5×
1 |
3 |
=-1-[1-(1-
1 |
2 |
1 |
3 |
=-1-6+6-
1 |
2 |
1 |
3 |
=-1-6+6-1
=-2;
(5)-22-(-3)3×(-1)4-(-1)5
=-4+27×1+1
=-4+27+1
=24;
(6)(-
5 |
8 |
=-
5 |
8 |
=-10-80
=-90;
(7)(-1)+(-1)2+(-1)3+…+(-1)99+(-1)100
=-1+1-1+…-1+1
=0;
(8)
1 |
5×9 |
1 |
9×13 |
1 |
13×17 |
1 |
101×105 |
=
1 |
4 |
1 |
5 |
1 |
9 |
1 |
4 |
1 |
9 |
1 |
13 |
1 |
4 |
1 |
13 |
1 |
17 |
1 |
4 |
1 |
101 |
1 |
105 |
=
1 |
4 |
1 |
5 |
1 |
105 |
=
1 |
21 |
点评:考查了有理数混合运算顺序:
(1)先算乘方,再算乘除,最后算加减;同级运算,应按从左到右的顺序进行计算;如果有括号,要先做括号内的运算.
(2)进行有理数的混合运算时,注意各个运算律的运用,使运算过程得到简化.
(1)先算乘方,再算乘除,最后算加减;同级运算,应按从左到右的顺序进行计算;如果有括号,要先做括号内的运算.
(2)进行有理数的混合运算时,注意各个运算律的运用,使运算过程得到简化.
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