The only thing that prevents this comic from being realistic is the correct calculation of 99 choose 2 on the fly. That would require at least two napkins.

Not that difficulty to work out in the head actually:
$${99 \choose 2} = 99*98/2= 99*49=50*100-50-100+1 .$$ Would still require \ldots in the speach bubble, though.

Sylvia, you’ve got to have some finite limit here… We are but mortal. I like to go with “n bottles of beer on the wall”, and when it turns out that someone needs to be cut off, you let n=[the number of beers consumed]. It’s worked great for me. :D

Also, I was going to make a similar comment to that made by 31459295 (missing a 1 somewhere?), but I was beaten to it.

The typical mental math trick is:
x=10^2
We’re not in a field of finite characteristic, so …
(x-1)(x-2)/2 = (1/2)(x^2-3x+2)
= (1/2)(10^4 – 3.10^2 +2)
… and the rest can be done about as fast as it can be read out loud.

There’s an easy way to do general multiplications 999…99 * ABC…YZ: First write the number ABC…YZ – 1, and next to it the 9-complement of each digit of this number. For instance, 9999*6481=64803519.

Actually, the calculation is extremely simple:

99 choose 2 = 99 * 98 / 2 = 99 * 49 = 100 * 49 – 49 = 4900 – 49 = 4851

surely everyone knows 4,851 is Ramanujan’s bottle number?

Not that difficulty to work out in the head actually:

$${99 \choose 2} = 99*98/2= 99*49=50*100-50-100+1 .$$ Would still require \ldots in the speach bubble, though.

Aleph naught bottles of beer on the wall

Aleph naught bottles of beeee-eer

Take one down,

Pass it around

Aleph naught bottles of beer on the wall.

(Now that is my kind of bar, assuming it is good beer.)

Okay, I’m certain you’ve heard that one before.

Sylvia, you’ve got to have some finite limit here… We are but mortal. I like to go with “n bottles of beer on the wall”, and when it turns out that someone needs to be cut off, you let n=[the number of beers consumed]. It’s worked great for me. :D

Also, I was going to make a similar comment to that made by 31459295 (missing a 1 somewhere?), but I was beaten to it.

@Cory: I’ll give you that. Most people I know are not *that* much fun after a certain n bottles of beer.

Actually the calculation is extremely simple:

(99*90+99*8)/2 = (8910+792)/2=9702/2=4851

It’s just two digit multiplication guys. No tricks necessary.

Simpler yet, there are 99C2 combinations, let applied mathematicians or engineers worry what integer that actually is.

@Kenny – You and I think alike. ;)

The typical mental math trick is:

x=10^2

We’re not in a field of finite characteristic, so …

(x-1)(x-2)/2 = (1/2)(x^2-3x+2)

= (1/2)(10^4 – 3.10^2 +2)

… and the rest can be done about as fast as it can be read out loud.

There’s an easy way to do general multiplications 999…99 * ABC…YZ: First write the number ABC…YZ – 1, and next to it the 9-complement of each digit of this number. For instance, 9999*6481=64803519.