16 December 2013

Size Matters

Size Matters 

Do your students know their bytes and pixels from their mega/kilo/giga/tera bytes? Thanks to an outdated emphasis on traditional units of measurements, this is extremely unlikely.



Unfortunately our antiquated education systems have yet to realise that in the 21st century the units of measure that matter most are not kilograms or kilometres, or cm or even mm—sure they are important, but what measurements do we deal with daily? The measurements of computer memory and particular of pixels. Any yet, ask yourself, how often do we set our students situations in mathematics that requires them to learn or use these units of measurements—NEVER—why? The sad truth is that most educators know as little about these units of measurement than most of their students. That, is a travesty.

So, here's the skinny:

The smallest unit of memory is a bit, then a byte, and they go up in thousands from there, so a thousand bytes in a kilobyte, a thousand kilobytes in a megabytes... and so on.

Here's a simpler way to imagine it...




1 bit (short for binary digit) = teeny tiny, the smallest size you can get, and yes, useless to almost everyone.

1 byte (b) = 1 character in the alphabet, eg the letter 'a'. = still useless

1 kilobyte (Kb) = 1000 bytes = 1000 characters, eg, a page of text = now we're getting somewhere...

1 megabyte (Mb) = 1000 Kilobytes = 1000 pages of text = 1 large digital image = 1 minute of music (mp3)


5 megabytes = 5,000 kilobytes = 5,000 pages of text = 1 very large digital image = a 5 minute song (mp3) This is pretty much the upper limit for email attachments.

10 Megabytes = 10,000 KB = 10 large photos = 10 minutes of music = 1 minute of video.



1 gigabyte (Gb) = 1000 megabytes (MBs) = an entire film/movie

1 terabyte (Tb) = 1000 GBs = MASSIVE = Pretty much only relevant for storage, external hard-drives etc.

Yes there are more...
...

In a nutshell

bytes - pretty much useless, like a grain of rice, or an ant.

kilobytes (KB) like pages of text (text emails and small images would be measured in kilobytes) the most useful size online, not too small not too big. a bowl of rice, or a cat.

megabytes, now we're getting 'heavy' - large photos, music, 10 MBs or more for video. A 1 Kilo bag of rice, a large dog.

gigabytes, woah, that's big - high definition full length films, 1000s of high resolution images. A sack of rice, a small horse!

terabytes, OK, now we're talking massive - entire collections of films. A van loaded with sacks of rice, a large elephant!



Particulars about pixels


To confuse things, images use more memory than text, and are measured in pixels, which do relate to size, but are not the same thing. A laptop Pro screen is at least 1400 pixels wide, so that gives you an idea...

As a rough guide:

10 pixels square =  the size of one lower case letter = 1kb
100 pixels square = size of 4 desktop icons = 10kb
1000 pixels square = small/standard monitor (screen) size = 1 Mb
10,000 pixels square = large/high definition (size of a door), high resolution image/poster = 10 Mb


So when Googling images, a pixel size of about 500px is ideal, 50px is too small (blurry) and images in the 1000s are probably too big (takes ages to load, and display).


So, what is the next step? Take some time to plan some problems solving scenarios in a Maths lesson that use some 21st century units for a change.