A fun math trick :)

Dear Einstein,

Don’t forget the advise on NOT finding out our weight. And before I forget, we’re sensitive on the age thing too…well, not all of us – only those that surpass a certain age.

Yours Sincerely,

Ally

27.  What's my height and weight?  ;)

hint: just make the answer flattering.  I of course would reply, "That's right!," and everyone will think you have a really neat trick. 

That was cool.  Got the proof.  Thanks.  Gleaned it while it was here temporarily.   Learn something new every day.

einstien how did u know that? are u sum kind of mathmatician... ??? lol

2+3=5, 9-5=4. Didn't I explain this?

cool

lol nice maths

lol still dont understand it

easy I figured it out

Here's how I did it

                 33333 is my number they add to 15. 33333-15=33318. Say I cross an 8. I add up 3,3,3, and 1, which is 10. 18 is one of the multiples of nine, and its a number closest to, but greater than 10. 18-10= 8

12345 = 1*(9999+1)+2*(999+1)+3*(99+1)+4*(9+1)+5*(0+1) = 1*9999+2*999+3*99+4*9+5*0 + 1+2+3+4+5 = 9*(1*1111+2*111+3*11+4*1+5*0) + 1+2+3+4+5

Every number minus the sum of its digits is a multiple of nine. Similarly, every multiple of nine has the sum of its digits a multiple of nine. Now, crossing out a digit and then summing is identical to summing and then subtracting the digit. Therefore, the only non-zero digit such that the answer sums to a multiple of nine is the digit crossed.

 nice work  :)

Is that the final sum you came up with?  :)  It is a huge sum.  If it is then you crossed out a 3.  :)

K

K

I know I’m late but I have a sum u can’t do the trick on

It’s not base 10 btw hehehe