算算你的電話號碼---很神奇的噢

Here is a math trick so unbelievable that it will stump you. Grab a calculator. (you won\'t be able to do this one in your Head)

1. Key in the first four digits of your fixed line telephone number (NOT the Area code)

2. Multiply by 80

3. Add 1

4. Multiply by 250

5. Add to this the last 4 digits of your phone number

6. Add to this the last 4 digits of your phone number again.

7. Subtract 250

8. Divide number by 2

Do you recognize the answer?