题目内容
计算下面各题,能简算的要简算. 102×45= |
8.76-5.29-2.71+1.24= | 3.31-18.3÷7×0.5= | ||||||||||||||||||
1-(
|
24×
|
|
分析:102×45,转化为:(100+2)×45,运用乘法分配律简算;
8.76-5.29-2.71+1.24,根据加、减法的运算性质简算;
3.31-18.3÷7×0.5,把除数转化为乘它的倒数,然后先算乘法,再算减法;
1-(
+
)×
,运用乘法分配律简算;
24×
+51×
,转化为24×
+19×
,再运用乘法分配律简算;
÷(
-
)×
,先算括号里面的,再算除法、乘法.
8.76-5.29-2.71+1.24,根据加、减法的运算性质简算;
3.31-18.3÷7×0.5,把除数转化为乘它的倒数,然后先算乘法,再算减法;
1-(
1 |
5 |
1 |
3 |
15 |
8 |
24×
51 |
43 |
19 |
43 |
51 |
43 |
51 |
43 |
9 |
14 |
5 |
6 |
3 |
4 |
7 |
24 |
解答:解:102×45
=100×45+2×45
=4500+90
=4590;
8.76-5.29-2.71+1.24
=8.76+1.24-(5.29+2.71)
=10-8
=2;
3.31-18.3÷7×0.5
=3.31-18
×
×
=3.31-
×
×
=3
-
=
-
=
-
=
=2
;
1-(
+
)×
=1-
×
-
×
=1-
-
=0;
24×
+51×
=24×
+19×
=(24+19)×
=43×
=51;
÷(
-
)×
=
÷
×
=
×12×
=
.
=100×45+2×45
=4500+90
=4590;
8.76-5.29-2.71+1.24
=8.76+1.24-(5.29+2.71)
=10-8
=2;
3.31-18.3÷7×0.5
=3.31-18
3 |
10 |
1 |
7 |
1 |
2 |
=3.31-
183 |
10 |
1 |
7 |
1 |
2 |
=3
31 |
100 |
183 |
140 |
=
331 |
100 |
183 |
140 |
=
2317 |
700 |
915 |
700 |
=
1402 |
700 |
=2
1 |
350 |
1-(
1 |
5 |
1 |
3 |
15 |
8 |
=1-
1 |
5 |
15 |
8 |
1 |
3 |
15 |
8 |
=1-
3 |
8 |
5 |
8 |
=0;
24×
51 |
43 |
19 |
43 |
=24×
51 |
43 |
51 |
43 |
=(24+19)×
51 |
43 |
=43×
51 |
43 |
=51;
9 |
14 |
5 |
6 |
3 |
4 |
7 |
24 |
=
9 |
14 |
1 |
12 |
7 |
24 |
=
9 |
14 |
7 |
24 |
=
9 |
4 |
点评:此题考查的目的是理解掌握小数、分数四则混合运算的顺序以及它们的计算法则,并且能够灵活选择简便方法进行计算.
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