Look around you maths

This British comedy show is hilarious. It’s called “Look Around You” and the second epsidoe is about “Maths”. Check it out on youtube (at least for now):

Quote from the show (but you really have to watch it to put it in perspective!!):

Narrator: What’s the largest number you can think of ?
Person 1: 100,000
Person 2: 999,000
Person 3: a million!
Narrator: In actual fact it’s neither of these. The largest number is
about 45 billion, although mathematicians suspect there may be even
larger numbers!

And one of the problems they presented:

Narrator: Eight ladies go to eight shops at eight o’clock in the morning. Each
lady wants to buy eight spiders. For each spider, eight spider shoes
must also be bought. But they only have eight pounds between them. With
each spider costing eight pence and each spider shoe costing an eighth
pence each, will the ladies have enough change for the bus ride home? A
journey costing eight pence per stop and made up of eight stops.

Check out the wiki entry for more information.

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The mathematics of sudoku

Tom Davis has a great article on the mathematics of sudoku. He first describes a brief history of the puzzle and how to play. Then he discusses why it is mathematically interesting (it is, trust me!). He goes through some obvious strategies that a lot of people try when doing sudoku and some other clever strategies. Definitely check it out if you have time!


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Silly but trickly puzzle

So my PhD friends couldn’t solve the following problem…

3489 = 4
8410 = 4
9120 = 2
8328 = 4
2210 = 1
9910 = 3
9900 = 4
7172 = 0
3884 = 5
9889 = 6
9009 = 4
0911 = 2
8888 = 8

What is 3859?

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Math cheat sheets

People love to cheat at math for some reason (laziness? lack of understanding? failure to get help?)… anyways, here are some math cheat sheets you can use from different websites:

The first one is about algebra, it has 23 pages filled with formulas:
Algebra Notes

The next one is much shorter about algebra again (4 pages): Algebra Cheat Sheet.
This next one is calculus:
Calculus Cheat Sheet (6 pages of Calc notes).

For computer science formulas see Computer Science Cheat Sheets. (10 pages)

For Geometry you can look at the Geometry Fact Sheet.

The next one is: Astrophysics and more.
This one has a bunch regarding calc, multivariable calculus cheat
sheets, physics, quantum mechanics, optics, astrophysics, relativity,
and more more more!! You can view / save as a jpg and print 😀

For more physics / calc you can look at these ones:Physic and Calculus Cheat Sheets (zip files for easy download).

And finally some trig here: Trigonometry Cheat Sheet .

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Calculator for grades K-3

This calculator is perfect for all those kindergartners who need to do some math… quoted from the website:

The TI-10 is perfect for the primary grades. It combines popular
features of the TI-15 Explorer™, which makes it a unique tool for
grades K-3. The TI-10’s comfortable, colorful design helps students
find patterns in daily activities and helps educators reinforce math
concepts in all elementary subjects.

Please, please, pleaseeee don’t let kids that young use calculators!!
And if they do, only let them use it to check their answers.

Say you have two kids who have to add up the numbers from 1 to 100. The calculator kid would use his monkey sticks calculator and plug away at it. The non-calculator kid would hopefully come up with a thoughtful solution to the problem (sound familiar?) 😀

I guess it doesn’t matter since it’s computer age now. Lots of grade 9
students can’t even properly WRITE their own name! They never ever have
to write (and rarely sign forms), and only learned to properly write in
grade 3 (the curriculum was set to focus more on teaching kids
computers). Oh monkey sticks, what will we do ^_^

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Cat picture

This is a cute picture 😀

cat meow mu comic picture

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Math fails in history

Dick Lipton wrote a great post over at Gödel’s Lost Letter and P=NP. In his Sept 27th post he talked about surprises in mathematics. In one of his sections he gives three examples of where mathematicians “accepted” a false proof. Sometimes this happens and it might be dozens of years until someone realizes a mistake has been made.

One interesting example of this is the Four Colour Theorem (that’s right ya bunch of monkeys, I spelled colour with a U!!!)…
Lipton says…

Four-Color Theorem (4CT) dates back to 1852, when it was first proposed
as a conjecture. Francis Guthrie was trying to color the map of
counties in England and observed that four colors were enough.
Consequently, he proposed the 4CT. In 1879, Alfred Kempe provided a
“proof” for the 4CT. A year later, Peter Tait proposed another proof
for 4CT. Interestingly both proofs stood for 11 years before they were
proved wrong. Percy Heawood disproved Kempe’s proof in 1890, and Julius
Petersen showed that Tait’s proof was wrong a year later.

However, Kempe’s and Tait’s proofs, or attempts at a proof, were not
fully futile. For instance, Heawood noticed that Kempe’s proof can be
adapted into a correct proof of a “Five-Color Theorem”. There were
several attempts at proving the 4CT before it was eventually proved in
1976. See this article by Robin Thomas for a historical perspective of
the problem.

Go check out the rest of his post NOW.

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Another Spiked Math comic

Today’s spiked math comic isn’t too shabby (idea by ma bro):

 condom math comic

As a mathematician, assumptions are things that come natural to us 😀

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Another (x, why?) comic :-D

okay okay, but this one is very funny (at least to me)… units are great 😀


I remember marking papers and on NUMEROUS occasions a student would write down such a bizzarro answer it made me LOL in real life!! One of these days i’ll write a post dedicated to some of the hilarious “mistakes” i’ve seen.

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How many guys are there for me?

Hey guys,

Based on my previous post of “How many girls are there for me,” I thought it would be interesting to see how many guys there are for me. So hypothetically let’s pretend I am gay and a top (if you don’t know what that means you should get some more gay friends lol). Just a recap that I found out in the last post that:

11, 414 girls

are suitable matches for me.

Now, some of my stats I used from counting the number of girls for me still hold. The male population on the planet is about:

Male population on earth in 2009:

But I am looking for a boy who is in North America. Restricting this number to Canada and the United States gives:

171, 230, 000 boys

He must also be around my age. Say, from 25-29 years old. That leaves:

11, 415, 000 boys

But about half of these boys are already married or in a common-law relationship. Thus, that leaves:

5, 707, 500 boys

And further, about 89% of men are not interested in men (i.e. straight or other). That leaves:

627, 825 boys

Being a mathematician, I want a boy who is smart. But a lot of gay guys are actually smart (unlike the other post which quoted: 85% of girls in North America are complete dumb asses). Only about 50% of gay guys are complete dumbasses, thus that leaves:

313, 912 boys

I don’t want no ugly man! Thank god that a lot of gay guys take
care of their appearance and work out at the gym. About 40% of gay guys
don’t, so that leaves:

188, 347 boys

But the boy must also like me. To see what kind of statistic is
reasonable, I went to the local gay bar and chatted with 10 boys. Then
the end I asked them if they liked me based on my appearance and our
conversation. An outstanding 7 boys said yes and wanted to go back to
my place. But upon further asking, 5 of them didn’t want an actual
relationship with me. So, only about 20% of the boys actually like me
and would date me. That leaves:

37, 669 boys

Finally, as I said at the top, hypothetically speaking I would be a
“top” gay. So, assuming that 50% are also tops, that would leave me

18, 834 boys

Holy cow!! WTF!? So only 11, 414 girls would make a perfect match with
me, but if I were gay, an outstanding 18, 834 boys would make a perfect
match with me! Damn, I better reconsider my options LOL.

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