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CHAPTER 1
NUMBER SYSTEMS
LEARNING OBJECTIVES
Learning objectives are stated at the beginning of each chapter. These learning objectives serve as a
preview of the information you are expected to learn in the chapter. The comprehensive check questions
are based on the objectives. By successfully completing the NRTC, you indicate that you have met the
objectives and have learned the information. The learning objectives are listed below.
Upon completion of this chapter, you should be able to do the following:
1. Recognize different types of number systems as they relate to computers.
2. Identify and define unit, number, base/radix, positional notation, and most and least significant
digits as they relate to decimal, binary, octal, and hexadecimal number systems.
3. Add and subtract in binary, octal, and hexadecimal number systems.
4. Convert values from decimal, binary, octal, hexadecimal, and binary-coded decimal number
systems to each other and back to the other systems.
5. Add in binary-coded decimal.
INTRODUCTION
How many days’ leave do you have on the books? How much money do you have to last until
payday? It doesn’t matter what the question isif the answer is in dollars or days or cows, it will be
represented by numbers.
Just try to imagine going through one day without using numbers. Some things can be easily
described without using numbers, but others prove to be difficult. Look at the following examples:
I am stationed on the aircraft carrier Nimitz.
He owns a green Chevrolet.
The use of numbers wasn’t necessary in the preceding statements, but the following examples
depend on the use of numbers:
I have to last until payday.
I want to take 14 days’ leave.
You can see by these statements that numbers play an important part in our lives.
