Cool Math Trick

this math trick is really cool , just try it !

1. grab a calculator ( you won't be able to do this one in your head)
2. key in the first three digits of ur phone number ( NOT the area code-if ur number is 021-123-4567, the first digits are 123)
3. multiply by 80
4. add 1
5. multiply by 250
6. add the last 4 digits of ur phone number
7. add the last 4 digits of ur phone number again
8. subtract 250
9. divide number by 2

Do You Recognize the answer ? :9

nb :
*multiply = di kali
*divide = dibagi
* add = dijumlah / tambah
* subtract= dikurang