青岛版小学四年级下册数学 怎么简便怎么做 练习题答案

2024-12-04 09:50:42
推荐回答(2个)
回答1:

(1)101×99
=(100+1)×99
=100×99+99
=9999
(2)14×35
=7×2×35
=7×70
=490
(3)25×28
=25×4×7
=100×7
=700
(4)4×9×25
=4×25×9
=100×9
=900
(5)43×5×4
=43×20
=860
(6)15×12
=15×2×6
=30×6
=180
(7)12×(40-5)
=12×40-12×5
=480-60
=420

(8)64×9-14×9
=(64-14)×9
=50×9
=450

(9)35×98
=35×(100-2)
=35×100-35×2
=3500-70
=3430

(10)23×134-34×23
=23×(134-34)
=23×100
=2300

(11) 957+(128-157)
=957-157+128
=800+128
=928

(12) 706-399
=706-400+1
=307

回答2:

学习是自己的