题目内容
递等式计算,能简便的要简便. 26×99 | 9×99+99 | 15×8×125×20 |
4600÷92 | 4500÷125 | 7800÷4÷25 |
考点:运算定律与简便运算
专题:运算定律及简算
分析:(1)把99化成(100-1),再运用乘法分配律进行简算;
(2)运用乘法分配律进行简算;
(3)运用乘法交换与结合律简算;
(4)(5)(6)根据除法的运算性质进行简算即可.
(2)运用乘法分配律进行简算;
(3)运用乘法交换与结合律简算;
(4)(5)(6)根据除法的运算性质进行简算即可.
解答:
解:(1)26×99
=26×(100-1)
=26×100-26×1
=2600-26
=2574;
(2)9×99+99
=(9+1)×99
=10×99
=990;
(3)15×8×125×20
=(15×20)×(125×8)
=300×1000
=300000;
(4)4600÷92
=4600÷(46×2)
=4600÷46÷2
=100÷2
=50;
(5)4500÷125
=4500÷(5×5×5)
=4500÷5÷5÷5
=900÷5÷5
=180÷5
=36;
(6)7800÷4÷25
=7800÷(4×25)
=7800÷100
=78.
=26×(100-1)
=26×100-26×1
=2600-26
=2574;
(2)9×99+99
=(9+1)×99
=10×99
=990;
(3)15×8×125×20
=(15×20)×(125×8)
=300×1000
=300000;
(4)4600÷92
=4600÷(46×2)
=4600÷46÷2
=100÷2
=50;
(5)4500÷125
=4500÷(5×5×5)
=4500÷5÷5÷5
=900÷5÷5
=180÷5
=36;
(6)7800÷4÷25
=7800÷(4×25)
=7800÷100
=78.
点评:此题考查学生灵活运用运算定律简算的能力.
练习册系列答案
相关题目