## Digital Data Quest

posted by: Mr. Bergquist 18 September 2012 One Comment

We’ve learned that all computer devices (i.e. cell phones, game consoles, tablets & PC’s) store their information digitally in binary – a numerical system with only two states, which we generally think of as a sequence of ‘0’s and ‘1’s.  Here are two version of this Exercise to use: Digital Data Quest PDF you can print, AND Here is a Blank Word Doc you can download & edit (save to our S:Drive location later.)

In this webquest, you’ll use some websites as well as your favorite search engine to answer a series of questions related to digital data storage and representation. You should come away with a better understanding of how information is used by our devices.  Write your answers on a sheet of paper or save them in a Word file on the computer in our Classroom Shared folder under (make sure your name is in the document):
My Computer > S: > embergquist > Writeable > Exploring CS > Class Period # > – include your name in file name.

## Data Storage:

1. To represent the number 5634, how many bits do I need? (try search for ‘5634 in binary’ using Google – each position in a binary number is one “bit”)

2. The largest harddrives currently on the market have a capacity of approaching 60 terabytes .  How many bits are in one terabyte?  (Remember: 8 bits are in 1 byte – that might be on a test some day.)

3. Roughly how many MP3s can be stored in a Terabyte of space? How many hours of music is this?
NOTE: An MP3 has about 1 megabyte (MB) per minute (according to eHow ).

4. How are the bits (1′s and 0′s) encoded on a CD?  Hint: check out how CDs workPlease write your explaination in your own words – not just copy this – thanks.

## Digital images

1. As we discussed, colors in digital pictures are represented numerically. Designers and web developers often describe colors in hexadecimal. What is hexadecimal and how is it related to binary?  Why do you think that they use Hexadecimal instead of Binary numbers?
2. Use a color chart and write how your favorite color is represented both in hexadecimal (HTML code) AND in decimal (three values for red, green and blue).
3. Search to find what is “lossless” compression and give two examples of common image formats that are lossless.
4. Search to find what is what is “lossy” compression? and give determine what common image file format is lossy?

(Adapted from Ms Martin’s Digital Data Representation and Storage).

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