1 / 10

算一算

算一算. 6×3= 6×30= 60×30=. 14×2= 14×20= 140×2=. 25×2= 25×20= 250×20=. 18. 28. 50. 500. 180. 280. 1800. 280. 5000. 动动笔. 计算 :23×12. 算法 3 2 6 × 2 1 2 6 5 2 5 4 6. 算法 1 26×20=520 26×1=26 520+26=546. 算法 2 21×20=420 21×6=126 420+126=546. 算法 4 26×21

quennell-poirier
Download Presentation

算一算

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 算一算 6×3= 6×30= 60×30= 14×2= 14×20= 140×2= 25×2= 25×20= 250×20= 18 28 50 500 180 280 1800 280 5000

  2. 动动笔 计算:23×12

  3. 算法3 2 6 × 2 1 2 6 5 2 5 4 6 算法1 26×20=520 26×1=26 520+26=546 算法2 21×20=420 21×6=126 420+126=546 算法4 26×21 =26×3×7 =78×7 =546

  4. （1）24×28 （2）15×36

  5. 数学门诊 2 3 × 1 2 4 6 2 3 2 7 6 ① 4 2 ② 2 3 × 2 6 ×1 2 2 4 2 4 6 8 4 2 3 10 8 2 6 9 4 2 × 2 6 2 5 2 8 4 1 0 9 2 下面的计算对的打”ν”,错的打”×”,并改正。 × × × ( ) ( )

  6. (1) 计算。 50 100 150 200 （2） 观察上述算式，想一想不计算能直接得到16×25的结果吗？ 16×25= 400

  7. 哪把钥匙能开百宝箱？

  8. 两位数乘两位数的计算方法: 先用两位数个位上的数去乘另一个因数,得数的末位和两位数的个位对齐;再用两位数十位上的数去乘另一个因数,得数的末位和两位数的十位对齐;然后把两次乘得的数加起来。 注意进位！

More Related