Friday, March 27, 2015

BODMAS

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(C)Copyright 2015, C. Burke.

I thought about ending with a comment about their trainer, Mr. Bechdel, but I thought better of it.

BODMAS is another mnemonic for the Order of Operations, just as PEMDAS is. I don't know if it's a regional thing, or what people learned in grad school or what.

Seriously, I didn't learn "PEMDAS" until I started teaching, and that was my second career.






Come back often for more funny math comics. Okay?




Wednesday, March 25, 2015

The 0'Factor, Episode 16

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(C)Copyright 2015, C. Burke.

Pi doesn't do rational conversations so well . . .

Bringing back some of the oldies before I hit 1,000 comics.

So what am I missing? What topics haven't I done? Or haven't done in a while? What are your favorites? Likes/Dislikes? (Almost sounds like a superficial interview.)






Come back often for more funny math comics. Okay?




Tuesday, March 24, 2015

(blog) Burke, the Virus Killer!

Okay, maybe that's a little over-dramatic and teensy bit overblown, but I did get hit with a virus at work which I thought had irrevocably scrambled my flash drive, rendering my files -- including my just-finished grades spreadsheet, which was due about an hour later -- irretrievable. Never saying die, I was determined to fix my drive. And I did. When I tweeted my sigh of relief, I was asked to make a blog post of it to explain to others, in case it happens to them.

Keep in mind, this will only solve your problems if you're hit with this specific virus.

"Help! My Directories Have Turned to *.LNK files!"

So here's the story, in brief: I was using the computer in the school's Teachers Room. It's probably the oldest machine on the floor, or close to it. (There are newer machines, but by comparison -- well, in actuality, too -- this one is a relic.) It's so old that the Windows Paint I used to make comics had a copyright date of 2000. But it has MS Excel on it, which could read the EGG file, which is the spreadsheet teachers enter student grades into. I used Excel last week to update the file, inserting comments for some of the students, particularly those with failing grades. After I saved the spreadsheet, that's when the errors started. I had opened a Notepad file while I was working, but I couldn't save it. I didn't realize what had gone wrong at the time. (Little did I know.)

This computer also has a second problem: since the last break, it hasn't had wifi. Therefore, I had to track down a different computer to email this. I found my colleague had arrived and opened the lab. When I tried to attach the file to a spreadsheet, that's when I found out something had happened to the drive.

The folder, which was named 2015 Spring, along with another named 2014 Fall had the wrong icons. There were arrows on the icons, which you would see if they were shortcuts to other folders or files. When I clicked on 2015 Spring, instead of opening the folder and showing all those files, I got an error message about a corrupted picture file (where the *.LNK was apparently pointing).

Long story shorter (sorry, it was so brief after all): My directories were gone and I couldn't access anything that was in them. Only a couple of files in the root directory. About 75% of that disk was in use. Most, but not all, of the files were backed up at home. But the grade file was nowhere to be found.

I Googled it. (And Binged it as well.) I found others who this had happened to, and saw instructions about going into regedit or other system commands and tinkering with Things Users Were Not Meant to Know -- even if I was once a programmer.

Have you ever been struck by lightning from out of the blue?

After two periods of reading and fretting, something occurred to me. I'd seen this before. It had happened before.

Taking a guess, I'd probably say it was 8-10 years ago and my first flash drive. Like I said, this was an old PC -- maybe the virus has been waiting there all this time. What had happened to my drive wasn't as malicious as it appeared. It was just an illusion, but an illusion that might get me to reformat my drive to "fix" something that wasn't broken in the way I had though it had been.

The *.LNK files were NOT the remains of my directories. They were bogus files with the SAME NAMES as my directories. Here's the kicker: My directories were just fine. They hadn't been touched! (At least, as far as I can tell now, they haven't been.)

The virus had changed the system attributes of the directories to make them all both HIDDEN and SYSTEM files. Hidden made them invisible to normal viewing in Windows. System just made it that much more of a Pain In The Neck (with a capital "A") to undo this.

One frustrating little thing: I used to know how to make Windows show you all hidden and system files. Apparently, I don't anymore. Maybe the options aren't in the same place. I searched for procedures online, found some and they still didn't work. So I did what any former programmer would do. I threw away the GUI Interface, shut the Windows and then I got Down and DOS-y with it.

I opened an MS-DOS command box and fixed it Old School!

Typing the DIR command showed my nothing except my root files, the fake *.LNK files and an AUTORUN.INF file, which curiously had a timestamp equal to the viral infection. (Hmmmmmmmm.) Typing DIR /AH ordered the computer to show me the Hidden files -- and there were all my directories.

Next up was the ATTRIB command, where I found out that they both Hidden and System attributes had been turned on for those files. This is what I meant by System making it more difficult: I had to go back and read up on the ATTRIB command because it wasn't working. I kept getting an error.

Basically, you can't unhide a system file and you can't unsystem a hidden file. You have to undo them both together. So one at a time, I had to enter commands of ATTRIB -H -S ("directory name").

I got my directories back. They were visible and accessible and the files were still there.

I also deleted that AUTORUN.INF file, which is a Windows file, which may be useful for some things, but is open to corruption and misuse, as was the case here. There was no reason for it to be on my flash drive.

Everything is back to normal. I have warned a few people about that computer, but no one else has had a problem with it. In fact, I've used it before without nasty side effects. The only difference I can point to is using MS Excel this time. The virus is probably buried in some macro, out of my field of expertise. And it's probably been there for years (considering the last time I saw this particular attack). Since I'm not Admin, there isn't much else I can do other than avoid the computer and warn others, but at least if it strikes someone else, I'll have an idea what to do.

Monday, March 23, 2015

(x, why?) Mini: Narcissistic

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(C)Copyright 2015, C. Burke.

I love numbers, but some numbers love themselves even more!

FYI: A Narcissistic number is any number that is equal to the sum of each of its digits raised to a power equal to the number of digits in the original number. For example, 153 = 13 + 53 + 33 and 1634 = 14 + 64 + 34 + 44.

Unlike prime numbers, it can be shown that the number of Narcissistic Numbers (also called Armstrong numbers) is finite.






Come back often for more funny math comics. Okay?




Friday, March 20, 2015

The Superman Function

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(C)Copyright 2015, C. Burke.

You know the hardest part was finding a graph that would reasonably fit on the screen.

Alternatively, it could've been 0.5x5 + 1.5x4 - 2.5x3 - 7.5x2 + 2x + 6.
A toss of the coin, really.

And, LOOK! It's a co-ordinate plane! But watch out when it's Super 3-D because evil things start to appear!






Come back often for more SUPER funny math comics. Okay?




Thursday, March 19, 2015

(x, why?) Mini: Special Characters

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(C)Copyright 2015, C. Burke.

So what makes some characters more special than others? My father-in-law will tell you "No one's special."

You know "@" misses his place in the limelights.

One last thing: why do people *say* "Hashtag" before saying the word/phrase in the hashtag? It's a "hash" and the whole thing is the tag. It's like "PIN Number" or "ATM Machine", I guess.






Come back often for more funny math comics. Okay?




Tuesday, March 17, 2015

Happy St. Patrick's Day 2015!

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(C)Copyright 2015, C. Burke.

The comic is incorrect. It derives with respect to Snakes. There should be no respect to Snakes!






Don't you love funny math comics? I do.




Saturday, March 14, 2015

Have A Happy Pi Day! (Just Don't Set It to Music)

As you are obviously aware, if you read this blog or troll any other mathematically-inclined site, today is The Pi Day of Our Lives!

Don't worry, now! I'm not about to invoke a similar sounding song title by One Direction (although I did consider it) because I've used that song before. That's why I settled for Row, Row, Row Your Boat" yesterday. I made a little comment in that comic that I want to expand upon.

Did you know: you could take the digits 0-9 and map them to musical notes and by extension fill pages of music sheets with the first few hundred digits/notes of pi?

Did you know: if you did this, you could be sued for copyright infringement?

Because you wouldn't have been the first one to have the idea. Someone else did, and he recorded it, copyrighted it, and has defended that copyright against anyone who tried it later. Now, I realize that copyright is an important thing and that compositions need to be protected and all that ... But come on now!!!

This wasn't an original work created from the artist's soul. It's a series of numbers.

So while the law will tell you that he copyrighted a musical composition, your mind wants to scream "He copyrighted pi?"

Which is the reason I explicitly stated yesterday that the copyright applied only to the image and not to the numbers therein.

But what a thought that'd be!

Friday, March 13, 2015

Pi Day 2015 (A Day Early)

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(C)Copyright 2015, C. Burke.

You would be correct to celebrate at 9:26:54, but like with the Millennium, you'll miss all the fun.

Back in the old days, when Dad would tell stories about him and his buddy Archimedes, we used 3.14 as an approximation to pi, or sometimes 22/7 is slightly closer. For more accuracy, we had to use 3.1416 -- not 3.1415. For this reason, I included that parenthetical (8). Rounding is important is mathematics! And in science!

Not so much in Marketing. Did you buy a shirt? I didn't. I'd save it for tomorrow and then it'd be "old" whenever I wore it again. Awkward! As if being a math geek wasn't bad enough!

Speaking of tomorrow: I'm trying to keep to a pseudo-regular schedule, and Friday posts are more well-received than Saturday posts. Just saying. And marketing, too, I guess.

Happy Friday the 13th! and enjoy the best Pi Day of Your Life ... so far.






Don't you love funny math comics? I do.




Thursday, March 12, 2015

Thoughts About Inscribed Angles and Arcs

In the past year and a half or so, I've been assigned to team teach with several different math teachers. I've been assigned to different schools in Brooklyn, with different pacing calendars. Because of this, I have happened to be in Geometry classes with three other teachers as they covered the various topics relating to circles: diameters, radii, chords, tangent, secants, arcs and angles. This past week, something occurred to me as I watched and assisted in another lesson.

When presenting the initial definition of inscribed angles and stating the relationship between the inscribed angle, the central angle and the intercepted arc, I generally see the same initial image.

This is a fine place to start, with a dart-shaped object inside the circle, somewhat similar in form to the insignia of Star Fleet. (Well, that's why I like it.) But teachers have to make sure that they address possible misconceptions.

  • Note that angle AOB is formed by two radii, which by definition are congruent. Angle ACB is formed by two chords? Is chord AC congruent to BC? They look that like or at least look close enough that the student might believe that the teacher meant to draw them that way. In truth, they might be congruent, but they don't have to be.

  • Does the vertex of the inscribed angle have to be somewhere "behind" the center of the circle? The problem with the dart-like figure is that the center of the circle is situated between the two chords. This doesn't have to be true. Inscribed angles can have their vertex anywhere on the circle, with the exception of inside the intercepted arc being considered. If can be to the side so that the chords intersect the radii. It might be closer to the intercepted arc than the center of the circle. Points like this should be shown, although, admittedly, some points would be difficult to illustrate.


  • Another point rarely made: after covering that the central angle equals the intercepted arc and that the inscribed angle is half the size of the intercepted arc, the next logical step doesn't get taken. Compare multiple inscribed angles intercepting the same arc. What is their relationship? Why?



Finally, there's a Special Case, which doesn't have to be presented as such -- at least, not the first time they see it. I see the special case just given that if an inscribed angle intercepts a semicircle, usually marked off by a diameter, then the inscribed angle is ________. STOP! Don't tell them. Ask them to figure it out using the rule for inscribed angles. Remind them, if necessary, that a diameter is also a straight angle with the center of the circle as its vertex. What is the measure of a straight angle?


What kind of angle does it have to be? Will it always be that for every inscribed angle intercepting a semicircle? Why or why not? What kind of triangle is inscribed in the circle? What do we know about the other two angles (taken together)?

With a little more variation in the foundation of the material, students will be better prepared for more complicated problems with "busier" images with criss-crossing chords or inscribed triangles and quadrilaterals.

Wednesday, March 11, 2015

Funny Math Comics

This post is nothing but a blatant attempt to capitalize on the search terms "Funny Math Comics".

I'm doing this because when I searched Google images, I had to scroll very far to find three of my images. Out of those three, two were hosted on other sites (not mine) and the third was actually a comic about Shakespeare.

Worse than that was the Yahoo search for "Funny Math Comics" which again yielded three results, and none of them were on my page.

Maybe I should talk to some of the folks whose work appeared a lot. Or maybe I need to add "Funny" and "math" as comment tags.

Don't know.

(x, why?) Mini: Fun With Tetrominoes, 2

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(C)Copyright 2015, C. Burke.

Maybe they should ask J-Z.

Fun fact: the J and Z subway lines travel together from lower Manhattan out over the Williamsburg Bridge through northern Brooklyn and into Queens. They don't travel anywhere near the Nets play basketball.

For more on Tetrominoes, click here.