Unbelievable math trick!!!!

[CptHa]

Nice.

 

[Aegis]

It didn't work for me, because my phone number contains eight digits. :tongue:

 

[mula0207]

Not bad, but not very "unbelievable." All these little math tricks have a reasonable explanation. Here's this ones:

Supposing your phone number is represented by:
abc-defg

You could write the first number (1st 3 digits) as:
100a+10b+c

And the second number (last 4 digits) as:
1000d+100e+10f+g

Then the whole expression would come out to:
(((100a + 10b + c)(80) + 1)(250) + 2(1000d + 100e + 10f + g) -250) / 2

If you expand that you will get:
1000000a + 100000b + 10000c + 1000d + 100e + 10f + g

Therefore appearing on the calculator in the same order as in the original phone number:
abc-defg

what????:dunno: ...lol...math wizzes..waht can ya say

 

[jdb67]

This is based on a 7 digit number.... What if you have an 8 digit phone number like I do???

 

[Leezy]

KOOOOL TRICKS! :nanner:

 

[HeartBroker]

Neat trick, I learned something similiar in machine shop.

I wish I could remember it!