1. Information Representation
All information in the computer must be in the form of 1’s and 0’s.
An example of a binary digit:

2. Question?
How can numbers, letters, graphics, sounds, etc. be represented by a binary digit???

3. Facts About Base 10 The number 456 means
We have 4 units of hundred
We have 5 units of ten
We have 6 units of one
Values in Base 10 depend on the digit (4, 5, or 6) and the position (one, ten, hundred).

4. Base 10 table 1000’s 100’s 10’s 1’s 4 5 6 7 3 = 456 = 7367 LABELS
Note that in each position we can only use the numbers 1 to 9.
What if the labels were not multiples of 10?
What if they were multiples of 2?

5. What numbers can we use in the positions?
Base 2 table
LABELS
8’s
4’s
2’s
1’s =
What numbers can we use in the positions?
Only a 1 or a 0.

6. Base 2 table 8’s 4’s 2’s 1’s 1 = 2 in base 10 = 4 in base 10 LABELS
= 2 in base 10
= 4 in base 10
10 is pronounced one zero – not ten
= 1 units of 2 and none of 1
100 is pronounced one zero zero
100(one zero zero) = 1 unit of 4 and none of 2 or 1

7. Other information representation.
Letters are given a number representation defined by the ASCII code.
Colors are also given a numeric code.
Graphics are coded in pixels. A group of pixels defines a picture and is either on or off.

8. A pixel representation of an unfilled square and a triangle.