题目内容
| 计算 26×25×40 |
99×69 | ||||||||||
| 102×32 | 182×94+182×6 | ||||||||||
| 203×40 | 32×25 | ||||||||||
|
|
分析:(1)根据乘法结合律进行简算,
(2)把99化成100-1,再根据乘法分配律进行简算,
(3)把102化成100+2,再根据乘法分配律进行简算,
(4)根据乘法分配律进行简算,
(5)把203化成200+3,再根据乘法分配律进行简算,
(6)把32化成8×4,再根据乘法结合律进行计算,
(7)、(8)先算小括号里的运算,再算括号外的运算.
(2)把99化成100-1,再根据乘法分配律进行简算,
(3)把102化成100+2,再根据乘法分配律进行简算,
(4)根据乘法分配律进行简算,
(5)把203化成200+3,再根据乘法分配律进行简算,
(6)把32化成8×4,再根据乘法结合律进行计算,
(7)、(8)先算小括号里的运算,再算括号外的运算.
解答:解:(1)26×25×40
=26×(25×40)
=26×1000
=26000;
(2)99×69
=(100-1)×69
=100×69-1×69
=6900-69
=6831;
(3)102×32
=(100+2)×32
=100×32+2×32
=3200+64
=3264;
(4)182×94+182×6
=182×(94+6)
=182×100
=18200;
(5)203×40
=(200+3)×40
=200×40+3×40
=8000+120
=8120;
(6)32×25
=8×(4×25)
=8×100
=800;
(7)
-(
-
)
=
-
=
;
(8)
+(1-
)
=
+
=
.
=26×(25×40)
=26×1000
=26000;
(2)99×69
=(100-1)×69
=100×69-1×69
=6900-69
=6831;
(3)102×32
=(100+2)×32
=100×32+2×32
=3200+64
=3264;
(4)182×94+182×6
=182×(94+6)
=182×100
=18200;
(5)203×40
=(200+3)×40
=200×40+3×40
=8000+120
=8120;
(6)32×25
=8×(4×25)
=8×100
=800;
(7)
| 7 |
| 15 |
| 13 |
| 15 |
| 11 |
| 15 |
=
| 7 |
| 15 |
| 2 |
| 15 |
=
| 1 |
| 3 |
(8)
| 7 |
| 12 |
| 11 |
| 12 |
=
| 7 |
| 12 |
| 1 |
| 12 |
=
| 2 |
| 3 |
点评:本题主要考查学生依据四则运算计算顺序进行计算,以及运用简便算法解决问题的能力.
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