1 / 19

五年級數學科

五年級數學科. 7. 乘數分配性質. 4 × 3 = 12. 每行有 4 個. 有 3 行. 共有 12 個. 4 × 2 = 8. 每行有 4 個. 有 2 行. 共有 8 個. 每行有 4 個圖案. 共有 5 行. 共有 20 個圖案. 4 × 5 = 20. =. 4 × 3. 12. +. 20. 4 × 2. 8. 4 × 3 + 4 × 2. 4. × 5.

hayley-mercado
Download Presentation

五年級數學科

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. 五年級數學科 7. 乘數分配性質

  2. 4 × 3 = 12 每行有4 個 有 3行 共有12 個

  3. 4 × 2 = 8 每行有4 個 有2行 共有 8 個

  4. 每行有4 個圖案 共有 5 行 共有 20個圖案 4 × 5 = 20

  5. = 4 × 3 12 + 20 4 × 2 8

  6. 4 × 3 + 4 × 2 4 × 5 3 行 + 2行 = 5 行 每行有4 個 ‖ 4 × ( 3 +2 ) = 20

  7. 12 cm 5 cm 周界 : 12× 2 +5 × 2= 34

  8. 12 cm 5 cm 周界 : 長× 2 + 闊× 2 = ( 長+闊) × 2

  9. 周界 : 12× 2 + 5 × 2 (長) (闊) = ( 長+闊) × 2 = ( 12 + 5 ) × 2

  10. 12 × 8+ 12 × 6 = 12 × ( 8+ 6 ) 35 ×14+ 35 × 26 = 35 × ( 14+ 26 ) 58 × 73+ 58 × 7 = 58 × ( 73+ 7 ) 22 × 5+ 45× 22 = 22 × ( 5+ 45 ) 7× 13+ 13 × 52 = ( 7+ 52 ) × 13

  11. 4 × 5 = 20

  12. 每行有4 個圖案 原本有 5 行 現除去黃色的 2 行 所以現在只有 綠色圖案12 個 4 × 3 = 12

  13. = 4 × 5 20 - 12 4 × 2 8

  14. 4 × 5 - 4 × 2 4 × 3 每行有4 個 5 行 - 2行 = 3 行 ‖ 4 × ( 5 -2 ) = 12

  15. 12 × 8- 12 × 6 = 12 × ( 8- 6 ) 35 ×14- 35 × 12 = 35 × ( 14- 12 ) 58 × 73- 58 × 7 = 58 × ( 73- 7 ) 22 × 45- 15× 22 = 22 × ( 45- 15 ) 75× 13- 13 × 52 = ( 75- 52 )× 13

  16. 練習 (一) ： 1. 7 × 15 + 7 × 5 = 7 × ( 15 + 5 ) 2. 22 × 18 + 22 × 12 = 22 × ( 18 + 12 ) 3. 37 × 42 + 42 × 63 = ( 37 + 63 ) × 42 4. 39 × 13 - 39 × 3 = 39 × ( 13 - 3 ) 5. 49 × 23 - 13 × 49 = 49 × ( 23 - 13 )

  17. 練習 (二) ： 1. 28 × 15 + 28 × 22 = 28 × ( 15 + 22 ) 2. 35 × 29 + 29 × 15 = ( 35 + 15 ) × 29 3. 42 × 8 + 28 × 8 = ( 42 + 28 ) × 8 4. 33 × 58 - 33 × 12 = 33 × ( 58 - 12 ) 5. 81 × 24 - 14 × 81 = 81 × ( 24 - 14 )

  18. 結論 : A × ( B + C ) = A × B+ A × C 例 : 2 × ( 12 + 5 ) = 2 × 12+ 2 × 5 18 × ( 7- 5 ) = 18 × 7- 18 × 5

  19. 比賽題目 ： 1. 31 × 45 + 31 × 15 = 31 × (45 + 15) 2. 21 × 45 + 21 × 15 = 21 × (45 + 15) 3. 87 × 8 + 12 × 87 = 87 × (8 + 12) 4. 83 × 11 + 11 × 42 = (83 + 42) × 11 5. 29 × 18 + 8 × 29 = 29 × (18 + 8)

More Related