Kind: captions
Language: en
[Applause]
Well, good afternoon ladies and
gentlemen. My name is Art Benjamin and I
am a math magician. What that means is I
combine my loves of math and magic to do
something I call mathematics. Does
anyone here happen to know the day of
the week that they were born on? All
right, starting with you. What year were
you born? 2004. 2004. And uh what month?
May. May. May what? 25th. 25th. Was that
a Tuesday? Yes. Yes. Good. Somebody
else. What year? Uh 2004. 2004. And what
month? August. August what? 17th. 17th.
Was that a Tuesday? Do we have any
faculty or staff who know the day of the
week? Okay, we've got one right here.
Uh, what year, if I may? 1970. 1970. And
what month? July. July what? 28th. 28th.
Was that a Tuesday? What is it with
Tuesdays in this
[Applause]
[Music]
state? The short answer is I'm taking
information from the year, the month,
and the date. I'm getting a number that
comes from each of those. I add those
three numbers together, and the total
tells me the day of the week. So every
year gets a code number and the code
number for
2015 happens to be four. Next we need a
code for every day of the week. And the
code numbers for Monday through Sunday
are 1 2 3 4 5 6 and Sunday is 7 or zero.
And that's real easy to remember because
Monday is one day. Tuesday is literally
Tuesday. Wednesday, if you put the W on
your fingers, that gives you the three.
[Music]
Finally, we need a code for every month
of the year. And the codes for January
to December uh go like this. It's not as
easy as you'd think. It's
622503514624. And to make it worse, if
it's a leap year, the codes for January
and February are 5 and 1. Okay. Yeah, I
know. Okay. Now, we have everything we
need to be able to figure out the day of
the week. So, uh, somebody give me their
birthday. November 15th. November 15th.
2015. What was the code for November?
Two. For the 15th, we add 15. And for
2015, we always add four. Four. And that
gives me 21. Now, every 7 days, the week
repeats. So, we can subtract any
multiple of seven and that won't change
the day of the week. So, I'll subtract
21 here, right? Cuz that's the biggest
multiple of 7. And 21 - 21 is zero. And
nunday is Sunday. Sunday. So your
birthday will be on a Sunday. Thank you
very much.
So cool.
Pi. Pi. Mathematical pie. Twice 11 over
7 is a mighty fine try. A good old
fraction you may hope to supply, but the
decimal expansion won't
die. Decimal expansion won't die. Pi pi
mathematical pi
3.141592653589. A good old fraction you
may hope to define, but the decimal
expansion won't
die. Thank you.
Thank you,
genius.