题目内容
用递等式计算,能简算的要简算.
(1)46×8-120÷15 | (2)
| ||||||||
(3)(12.5×8-40)÷0.6 | (4)3
| ||||||||
(5)3.4×0.77+0.34×2.3 | (6)(
|
考点:分数的四则混合运算,整数四则混合运算,小数四则混合运算
专题:运算顺序及法则,运算定律及简算
分析:(1)先同时运算乘法和除法,再算减法;
(2)运用加法交换律和结合律简算;
(3)先算小括号里面的乘法,再算中括号里面的减法,最后算括号外的除法;
(4)先同时运算乘法和除法,再算减法;
(5)运用乘法分配律简算;
(6)先把除法变成乘法,再运用乘法分配律简算.
(2)运用加法交换律和结合律简算;
(3)先算小括号里面的乘法,再算中括号里面的减法,最后算括号外的除法;
(4)先同时运算乘法和除法,再算减法;
(5)运用乘法分配律简算;
(6)先把除法变成乘法,再运用乘法分配律简算.
解答:
解:(1)46×8-120÷15
=368-8
=360;
(2)
+2
+
+3
=(
+
)+(2
+3
)
=1+6
=7;
(3)(12.5×8-40)÷0.6
=(100-40)÷0.6
=60÷0.6
=100;
(4)3
×
-1
÷2
=2-
=1
;
(5)3.4×0.77+0.34×2.3
=3.4×0.77+3.4×0.23
=3.4×(0.77+0.23)
=3.4×1
=3.4;
(6)(
+
-
)÷
=(
+
-
)×24
=
×24+
×24-
×24
=18+16-20
=34-20
=14.
=368-8
=360;
(2)
3 |
4 |
9 |
17 |
1 |
4 |
8 |
17 |
=(
3 |
4 |
1 |
4 |
9 |
17 |
8 |
17 |
=1+6
=7;
(3)(12.5×8-40)÷0.6
=(100-40)÷0.6
=60÷0.6
=100;
(4)3
2 |
5 |
10 |
17 |
3 |
4 |
1 |
3 |
=2-
3 |
4 |
=1
1 |
4 |
(5)3.4×0.77+0.34×2.3
=3.4×0.77+3.4×0.23
=3.4×(0.77+0.23)
=3.4×1
=3.4;
(6)(
3 |
4 |
2 |
3 |
5 |
6 |
1 |
24 |
=(
3 |
4 |
2 |
3 |
5 |
6 |
=
3 |
4 |
2 |
3 |
5 |
6 |
=18+16-20
=34-20
=14.
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.
练习册系列答案
相关题目
两个( )可以拼成一个平行四边形.
A、锐角三角形 | B、完全一样的三角形 |
C、直角三角形 |