题目内容
能简算的简算.
| (125+11)×8 | 63×102-63×2 |
| 25×28 | 67×67+33×67 |
| 125×32×25 | 99×32 |
| (750-690)÷5+88 | [218-(312-210)]×3. |
考点:整数四则混合运算,运算定律与简便运算
专题:运算顺序及法则
分析:(1)(2)(4)运用乘法分配律简算.
(3)把28看作4×7,御用乘法结合律简算.
(5)把32看作8×4,运用乘法结合律简算.
(6)把99看作100-1,运用乘法分配律简算.
(7)先算括号内的,再算括号外的除法,最后算加法.
(8)先算小括号内的,再算中括号内的,最后算括号外的.
(3)把28看作4×7,御用乘法结合律简算.
(5)把32看作8×4,运用乘法结合律简算.
(6)把99看作100-1,运用乘法分配律简算.
(7)先算括号内的,再算括号外的除法,最后算加法.
(8)先算小括号内的,再算中括号内的,最后算括号外的.
解答:
解:(1)(125+11)×8
=125×8+11×8
=1000+88
=1088
(2)63×102-63×2
=63×(102-2)
=63×100
=6300
(2)25×28
=25×4×7
=100×7
=700
(4)67×67+33×67
=67×(67+33)
=67×100
=6700
(5)125×32×25
=125×8×4×25
=(125×8)×(4×25)
=1000×100
=100000
(6)99×32
=(100-1)×32
=100×32-32
=3200-32
=3168
(7)(750-690)÷5+88
=60÷5+88
=12+88
=100
(8)[218-(312-210)]×3
=[218-102]×3
=116×3
=348
=125×8+11×8
=1000+88
=1088
(2)63×102-63×2
=63×(102-2)
=63×100
=6300
(2)25×28
=25×4×7
=100×7
=700
(4)67×67+33×67
=67×(67+33)
=67×100
=6700
(5)125×32×25
=125×8×4×25
=(125×8)×(4×25)
=1000×100
=100000
(6)99×32
=(100-1)×32
=100×32-32
=3200-32
=3168
(7)(750-690)÷5+88
=60÷5+88
=12+88
=100
(8)[218-(312-210)]×3
=[218-102]×3
=116×3
=348
点评:此题主要考查整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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