Welcome calculator fanciers; today we
have an unusual calculator to unbox. My
name is Matt Parker and here on
Numberphile I will be looking at this
Casio which is a well known calculator
brand; and they make other things but I
very much suspect this is not going to
be an electronic keyboard. In here is
some kind of calculator, although not in
the normal aspect ratio - very interesting.
And there's- there's scant
details outside, I mean look at- this
side's blank, that side's blank, I mean
that's an entire like a third of all
the faces on this box are blank. The only
real information here is that it's a
1-1 scale; which means that
whatever is in there is an exact
1-1 scale to what it is in
reality, that's quite- in fact most
physical objects tend to be a 1-1
scale. But anyway, so we'll pop this open,
we'll get our scalpel here; and again we're
going to very carefully use the scalpel
to just flick open the top there, right.
And if we open it up we can see - here we
go - it's a Casio data bank watch, oh yes.
You can see that they have covered it
with a kind of hood and it's
sufficiently transparent so you can
start to get excited about what's in
there, it's a little bit of a tease, but
the main reason they do that is so you
can have a grand unveiling. So you can
hold this and you can lift it off so and
then there you are - no better way
to open a calculator than that. And you
have a display stand! Ao when you bring
it home after a hard day of calculating
on the go you can put it back on the
display stand; it's got a special handle
there for picking up the display stand
should you not want to risk getting
fingerprints on the rest of it, and there
is a little spot here for the
instruction manual - look at that, just
crammed in there, they have shoved the
manual in there. Which if we fold it out;
so we get a variety of shapes should you
be uncertain as to what those shapes
would be. For California USA only! So if
you try and use this outside California
they cannot guarantee it will give you
mathematically accurate answers, that's
very good. What else is going to leap out?
Ok the rest of this is just
standard instruction booklet, although in
a slightly different ratio - this is the wide
screen version of the instruction
booklet which is great. So let's have a
look at the calculator itself, take it off
the stand.
This here, this is for adjusting where
this is, it can be there or there or
anywhere in between it's quite nice it's
a continuous thing; there's a
uncountably infinite number of places
you could put that it's quite nice. And
then there is there is a very finite set
number of places you can lock this into
position. So I feel like- I mean the main
feature of this is the fact that you can
attach it to your wrist, you can you can
strap it on and that is very important,
very few calculators can do that. In fact
I've got another for comparison Casio
calculator here; and if you try and
balance that on your- it's incredibly
difficult to do calculations on your
wrist, and should you be you know holding
a drink or something and you haven't got
the use of this hand and you need to do
a risk based calculation this is a
terrible idea; whereas this is going to
go on quite quite snugly and firmly and
you just slide that through there, here we go,
you adjust it to the- you round the diameter
well I guess usually the circumference of
your wrist to the nearest whole notch, you
flick that in there and you slide that
in there and then you choose one of the
uncountably infinite number of positions
you can put that. Although frankly - there -
it doesn't really move once it's on. So
that's that's quite quite tight actually,
I'm gonna- it also doubles as a tourniquet.
So it's got Casio in case you forget
where you buy it and water-resistant
alarm chrono.
So the chrono obviously for time
means that if it gets wet then the alarm
goes off. And then there's all sorts of
tiny tiny writing in there, there's lap
reset - should you be you know doing
competitive calculations and you're
timing yourself per lap. There's a date
thing, sig on off should you wish to turn
the sig on or off, start/stop alarm,
on/off and of course all the digits from 0
right through out to 9. Buttons on the
side over here; so that one there is
going to take- oh must be in
calculator mode. So let's do- let's just
do a calculation, so let's do 7
times - where's times?
There's a 6 - oh! Right okay
so I need to clear, where's
clear? What d'you reckon? Is that clear?
That's plus- that's plus! I'm adding- I'm
adding now. Now I'm adding and I wanted
to be clearing. What's that? That's- okay
let's try again so okay so
7 - it's 0.7! I've done 0.7-
okay maybe this is clear? That's clear
that's clear okay, right, of course. Why
waste a perfectly good button
repurposed for clearing. 7 times - good -
let's do 1/7 times
0.14285 - that's seven I hit seven -
4- because it's on the wrong- okay so
this is going to take some getting used to.
They're not well labelled as to which one
is which, I'm sure you'd get used to
that pretty quick. So 7 times
0.1428 - got it! - 57 - I'll
round up to a 2, shall we get 2 on the end
there? Equals - hey! Okay so it equals
1.00000004,
which I'm going to I'm going to allow
because I did round 1/7 a decent amount. Very
quickly do 1 divide 0
equals - error.
Just says E - that's good, that's good to
see. And we will do one quick test of
precision, so we'll do 1 divided by 9
times 9 equals - okay so again it hasn't
given is 1 it's given us
0.9999999 which- I mean given
the size I would say even though it's
not very accurate if you average the
accuracy versus size, or accuracy per
volume of the calculator, this one is
still doing pretty well. Like I said
before it does sit very neatly on your
wrist so it- and it moves with it, there's an
exact one-to-one match between where
your wrist is and where the watch ends
up which is quite nice. And and the big
feature is that we've deliberately got
the model of the Casio watch which
Walter White wears in Breaking Bad. And
so this watch is good for both
on-the-fly calculations when teaching
chemistry or cooking
methamphetamine. Scores for the Casio
data bank calculator watch: for the
display I gave it a 4, it's pretty
small. In terms of functionality a 2 - it's
the bare minimum. Accuracy 5; economics 10 -
I mean it's attached to your wrist. Cred - infinite.
Durability an 8 - it certainly
fared better than I was; which gives us a
grand total of infinity which is an
average of infinity. Because I'm not
allowed infinity as a score I can change
the cred to just go up to 11 which makes
a new total of 40, and that's an average
of 6.6 reoccurring.