Do you want to shuffle these Brady? Just so people are happy that they're not in a
pre-arranged order? - (Brady: I'm sure people believe us but there we go I've shuffled them up a bit.)
No I can't do that either, it's why I'm not attempting to do it on camera. Right,
so we've got a randomly shuffled pack of cards; I don't know the order they're in.
And I'm- first of all I'm just going to memorise them; so I'm just going to deal them out and
then try and remember whether they're red/black and then we'll go for it. Okay, let's go.
Okay, let's go for it. Umm, black, black
black, black, red, black
black, black, black, red, red, whoops.
Black
red
red, black, red, black
red
Black, black, red, black
Black, red,
black, red, red, red, red, red.
Ummm...red?
Red, red, red.
Black, black
Black?
Black, red, black.
Red, red,
black, red, red, black, black, black,
Final four! Red, black, red, red.
Yay! - (You happy with that?) - I'm very happy with that.
(Well done, very well done, amazing.) - Phew, genuine relief. - (Well done)
I think quite a few people watching might have spotted what I was doing based on the gaps
I was leaving. So when I was reciting them in particular, I was like- I wasn't reciting them
at a consistent pace. So I'd maybe- I think I'd do kind of six and then I'd often think for a bit
and then I'd do the next six. So I think that was a little bit of a clue that I'm grouping
these cards in to six - so groups of six. And I'll just give you an example, so the first one - now
I've got to remember what it was! The first one was- the first six was black, and then black, and then black,
um and then it was black again and then it was red and then it was black. So that was my first
group of six. What I'm doing is I'm taking the the second to the sixth of that group of six
um and I am- if it's a black card I'm thinking about a 1 in my head, and if it's a red card
I'm thinking about a 0 in my head. And so actually what I'm doing is I'm turning that
set of five into binary. So this is- this is a binary number, a string of 1s and 0s, and
then I'm turning that binary number into base 10 in my head. So in binary this represents one lot
of 1, zero lots of 2, and one lot of 4 and then I've got one lot of 8 and then I've got
one lot of 16. So this is 29, so this binary number represents 29. So I'm then remembering
29. So essentially I've condensed those five digits into this two-digit number.
(What about that first number?) - That's a good question; so this first one is in my head. Sometimes I remember
black as a negative and red is a positive, and sometimes I just remember it as black or red.
So essentially I found that I was much quicker and much more fluent if I just dealt with five
digit binary numbers; as soon as I got to the sixth um sixth digit I was getting- I was like, was it 37?
Was it 27? I was getting really confused. So I found it easier to think about that bit of
information just as it is, as like black or red. So for each of these groups it's either black or
red - and sometimes in my head I imagine the number as black or red. So literally this is black pen 29.
But then occasionally when I've been practicing I've been remembering it as minus 29 so
it changes. But this- just to be- just to be clear this isn't signed binary, right? So this
is literally just- this is the binary number and then this is just a separate bit of information.
So I had black 29, the next one I had was black 25, and then the next one..
- you're asking me! - was red 10. I think? And then the next one was black 22,
um and then the next one was black 0 which was really nice, that was quite a gift. And then the
next one was red, and it was 3 I think? And then the next one was black again; a lot of them were
black which was really helpful so I only had two reds here. And that was black 20 I think? And then it
was black 7. Each of these are six and there's eight of them so that's 48 cards only, so the final
four I'm just remembering as what they are. There's only- like not many patterns you can have with four
cards and it was red, black, red, red. So I just in my head I remember that as, the second one is black.
So that's what I was remembering. So essentially eight 1 or 2 digit numbers,
a bunch of blacks and reds. - (What's harder, the encoding or the decoding afterwards?)
The remember- and actually neither. So I guess there's three processes: the first process is encoding, so
turning it into the base 10 number; second process is just remembering it, and then decoding. Encoding
and decoding I've just practiced lots and lots, I'm really quick at it, so that's not
too hard it's the remembering. It's- it's kind of trying to encode in one part of your brain
whilst at the same time not forgetting all of the numbers that have already come through,
um and the patterns. So as I say, this was quite a nice one because - I'm not going to do my trick
down - but the fact that we've only got two reds and they had this kind of symmetry. So I see it like
this in my head, so I see I've got eight things to remember plus these little extra ones.
(Zero, is that a black card and then all reds?) - Yeah, exactly. So that was a black card and then five
reds so that was just really nice. Like I probably smiled when I dealt that out, so if you- if you
see on the- that was- yeah that was nice. And then also then in order to remember the numbers
um often- there's not too many patterns in this, well this one, but often if there's a pattern
that helps me remember it. So the other day I was practicing and I had something like 14 and then
7, that's half. Or another one I did the other day, I had 20 and then 3 and then 17; and 20
take 3 is 17. So if I can spot little patterns like that while I'm going along that really helps
me remember it. - (It almost feels like it'd be easier just to remember the 52 cards!)
I- yeah definitely not. Like I think I think the key with this is that I'm condensing the information.
So base 10 is much more efficient than binary. So this is effectively binary, right, so black
red's are the same as binary. And so I'm condensing like six or five digits down to one or two digits.
If you have a brain for numbers and you're about to start university, well this could be your moment.
Our episode sponsor, Jane Street, is running its Academy of Math and Programming. It's a five-week
summer program for recent high school graduates, particularly those who've experienced barriers to
access and opportunity. It's happening in July and all the expenses are paid including accommodation,
travel, and they're throwing in a $5,000 scholarship to support future opportunities.
If you're interested, or maybe you know someone who might be, check out the details on the Jane Street
website. All your questions will be answered there and I've also put a link in the video description.
Our thanks to Jane Street for their support.
...I've shown people this trick before and people have said, why don't you use hexadecimal?
Because you can represent eight digits, eight bits, with just like two- two digits. But I'm just- I'm just
nowhere near as practiced in that so it would be so much more difficult for me to remember things.