CS101.Lect11.BinaryNumbers.ppt

# CS101.Lect11.BinaryNumbers.ppt - CS101 Lecture 11: Binary...

This preview shows pages 1–7. Sign up to view the full content.

Computer Science CS101 Lecture 11: Binary Numbers Number Systems Binary Numbers Hexadecimal Aaron Stevens ([email protected]) 4 October 2011 Computer Science

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Computer Science Computer Science TODAY’S LECTURE CONTAINS TRACE AMOUNTS OF ARITHMETIC AND ALGEBRA PLEASE BE ADVISED THAT CALCULTORS WILL BE ALLOWED ON THE QUIZ (and that you probably won’t need them) !!! MATH WARNING !!!
Computer Science Overview/Questions What gives a number its value? What is a number system? I’ve heard that computers use binary numbers. What’s a binary number? What kind of numbers do computers store and manipulate? Computer Science 2 Natural Numbers Zero and any number obtained by repeatedly adding one to it. Examples: 100, 0, 45645, 32 Negative Numbers A value less than 0, with a – sign Examples: -24, -1, -45645, -32 Numbers

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Computer Science 3 Integers A natural number, a negative number, zero Examples: 249, 0, -45645, -32 Rational Numbers An integer or the quotient of two integers Examples: -249, -1, 0, 3/7, -2/5 Numbers Computer Science 4 A numbering system assigns meaning to the position of the numeric symbols. For example, consider this set of symbols: 642 What number is it? Why? Numbering Systems
Computer Science 5 It depends on the numbering system. 642 is 600 + 40 + 2 in BASE 10 The base of a number determines the number of digits (e.g. symbols) and the value of digit positions Numbering Systems Computer Science 6 Continuing with our example… 642 in base 10 positional notation is: 6 x 10 2 = 6 x 100 = 600 + 4 x 10 1 = 4 x 10 = 40 + 2 x 10º = 2 x 1 = 2 = 642 in base 10 This number is in base 10 The power indicates the position of the number Positional Notation

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
7 d n * B n-1 + d n-1 * B n-2 + . .. + d 1 * B 0 As a general form: 642 = 6 3 * 10 2 + 4 2 * 10 1 + 2 1 * 10 0
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 12/16/2011 for the course CS 101 taught by Professor Stevens during the Fall '08 term at BU.

### Page1 / 17

CS101.Lect11.BinaryNumbers.ppt - CS101 Lecture 11: Binary...

This preview shows document pages 1 - 7. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online