我的數學心算很差, 請教我好嗎?

👨🏻‍🏫 學術台數學

-.-膠花牌乳膠漆-.-

2007-09-25 9:16 am

7 x 7 = 49 (我一想就知道)
7 x 7 x 7 = 49 x 7 =...........計唔掂.
我講緊心算 !

更新1:

咁如果 17x17x17 呢 ?????

回答 (5)

[匿名]

2007-09-25 9:22 am

✔ 最佳答案

7 x 7 x 7 = 49 x 7 =( 50-1 ) x 7
=50 x 7 -1 x 7
=350 - 7
=343

參考: 自己

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用戶17048

2007-09-26 8:43 pm

17x17x17=17的3次方

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[匿名]

2007-09-25 10:47 am

I think you would like to improve 心算, you only need to practice, practice and practice in your daily life! :)

參考: My opinion

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風

2007-09-25 9:38 am

7 x 7 x 7
=49 x 7
=(40 x 7)+(9 x 7)
=280+63
=343

參考: me

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[匿名]

2007-09-25 9:23 am

7 x 7 x 7
= 49 x 7
= 50 x 7 - 7
= 350 - 7
= 343

I hope I can help you.

參考: my experience

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