燕山大学文法学院 刘妍:脑算乘法第75讲

来源:百度文库 编辑:偶看新闻 时间:2024/04/30 00:05:22

脑算乘法第75讲

(2010-01-13 10:11:48)转载 标签:

教育

分类:数学天地

脑算乘法第75

史丰收速算法,本个加后进,只记个的一位乘多位

    47530275×2=95060550。   473867×3=1421601。    24657×4=98628。 

 本个84060440                 219481                 86408 

后进01100011                 121222                 01222

 得积95060550                1421601 只记个            98628

按常规算法,斜看     

 个位 84060440                 219481                 86408

十位 01100011                 120212                 01222

 得积 95060550                1421601                 98628

 

    673284×5=3366420                      479237×6=2875422      

055000                                 424282

   331142                                 245124

   3366420                                2875422

 

379263×7=2654841。     462347×8=3698776。       874632×9=7871688

 193421                  286426                   236478

256142                  341235                   764521

2654841                 3698776                  7871688

 

习题:亲自练一练

      5843×2=11686         680332×3=2040996      75308×4=301232

              10347×5=51735         332668×6=1996008     

    428657×7=3000599       124625×8=997000      444726×9=4002534

分享

0

阅读(6) 评论 (0)收藏(0)转载 打印举报