AP Computer Science Principles Unit 1

Which of these values can be stored in a single bit? 1 -1.0 -4 -10

- 1

Which of these is a single byte of information? -11010 -101011010111 -10 -10101101

-10101101

Consider a computer that uses 5 bits to represent positive integers and uses all 5 bits to represent the value. Which of the following operations would result in integer overflow? (selected all that are correct) -12 x 12 -8 x 4 -18+14 -15+1

-8 x 4 -18+14

Digital alarm clocks display information and visual indicators to help people wake up on time; Which of the displays could be represented by a single bit? (TWO CORRECT answers) The current date (1-31) -the current day of the week -the current month (1-12) -the temperature unit indicator ( C or F) -the current hour (1-12) -the PM/AM indicator

-the temperature unit indicator ( C or F) -the PM/AM indicator

To avoid legal consequences, before using someone else's digital image they shared, you should...

...cite the image or get permission

What would be the decimal number 55 be in binary?

0011 0111

Take-aways from Binary

1. Binary can precisely represent SOME fractional amounts from the decimal number system 2. Binary cannot precisely represent other fractional values from the decimal number system (ex: 0.39)

What would be the decimal number 199 be in binary?

1100 0111

Your computer uses 4 bits to represent decimal numbers (0, 1, 2, 3 and so on) in binary. What is the SMALLEST number for which an overflow error occur?

16 Explanation: The 4-bit binary number 1111 represents the decimal number 15. Counting up to the next number, 16, will cause the 4-bit binary number to overflow to 0000 just like an odometer.

convert 1011 0010 to a decimal number?

178

lossless compression

A process for reducing the number of bits needed to represent something without losing any information. This process is reversible.

intellectual property

A work or invention that is the result of creativity, such as a piece of writing or a design, to which one has rights and for which one may apply for a patent, copyright, trademark, etc.

True or False: Abstraction SURFACES complex information

FALSE! Abstraction BURIES (hides) complex information

How many total numbers can be represented with an 8-bit binary (base-2) system?

256 Explanation: Binary is a base 2 number system. With each new bit, we double the amount of unique numbers we can make. With 7 bits, we can make the decimal numbers 0 to 127 (0000000 to 1111111), for a total of 128 unique numbers. When we go up to 8 bits, we can make the decimal numbers 0 to 255 (00000000 to 11111111) for a total of 256 unique numbers.

How many bits are used to encode one symbol in ASCII?

8

How many bits are required to store the text below in ASCII? Hello there!

8 X 12 = 96

byte

8 bits

creative commons

A collection of public copyright licenses that enable the free distribution of an otherwise copyrighted work, used when an author wants to give people the right to share, use, and build upon a work that they have created

How do computing devices represent information?

A computer represents data as bits which is either a 0 or a 1

Bit

A contraction of "Binary Digit". A bit is the single unit of information in a computer, typically represented as a 0 or 1. 8 bits = 1 byte 1000 bytes = 1 kilobyte 1000 kilobytes = 1 megabyte

What is an advantage of lossless compression algorithm over a lossy compression algorithm?

A lossless compression algorithm can guarantee the reconstruction of original data, while lossy compression algorithm cannot.

Prototype

A preliminary sketch of an idea or model for something new. It's the original drawing from which something real might be built or created.

sampling

A process for creating a digital representation of analog data by measuring the analog data at regular intervals called samples

lossy compression

A process for reducing the number of bits needed to represent something in which some information is lost or thrown away. This process is not reversible.

ASCII

American Standard Code for Information Interchange. ASCII is the universally recognized raw text format that any computer can understand.

True or False: Information created on a computer is not owned by anyone since only analog information is protected under copyright law.

False!

What kind of 'base' system is binary known as?

Base 2

digital data

Data that changes discretely through a finite set of possible values

analog data

Data with values that change continuously, or smoothly, over time. Some examples of analog data include music, colors of a painting, or position of a sprinter during a race

overflow error

Error from attempting to represent a number that is too large

roundoff error

Error from attempting to represent a number that is too precise. The value is rounded; can be caused when converting from decimal to binary)

Why do computers use binary?

Having only two clearly distinct states makes it easier, more reliable, and cheaper (in terms of materials, physical space required, and energy consumption) for machines to communicate.

when using binary to represent fractions of a number, can you create all possible fractions?

No because binary only supports 2 digits(which is either 0 or 1) therefore is not possible to do fractions out of it advertisement

What is significant about the way the ASCII table is organized?

Notice that the uppercase and lowercase letters were placed to line up. For example, in binary, "A" and "a" have a different prefix (0100 and 0110, respectively), but the same suffix (0001). "B" is written as 0100 0010, while "b" is 0110 0010. Notice also that the suffix indicates the first letter (0001), the second letter (0010) and so on.

Bit rate

The number of bits a second a system can transmit. e.g. 8 bits/sec.

Abstraction

Reducing information and detail to focus on essential characteristics. It is typically possible to look at a system at many levels of abstraction, depending on how much detail is necessary to approach the challenge at hand. To start a car, you only need to know how to turn the key or push a button, you don't need to know (or care) about the mechanics that actually start the car To send a text, you don't need to understand how it's converted into ASCII or Binary.

open source software (OSS)

Software that is free and where anyone can look at and potentially modify the code

What is the difference between a painting and a smartphone's photo of a painting?

The photo is a digital representation of the analog painting

What is an overflow error?

When the result of a binary calculation is too long for a computer to process

Binary

a way of representing information using only two numbers; a number system using base 2 with only 0 and 1

Why are lossy compression algorithms typically better than lossless compression algorithms at reducing the number of bits needed to represent a piece of data?

because with lossy compression data is being thrown away

With a fixed number of bits, some numbers are too large to represent in a computer which will lead to...

overflow errors

How do computers represent complex information?

patterns of bits, the same sequence of bits, abstractions such as numbers, characters, and colors.

open access research (OA)

the free, immediate, online availability of research outputs such as journal articles or books, combined with the rights to use these outputs fully in the digital environment. OA content is open to all, with no access fees

Code

to write instructions for a computer

When is it a good idea to use lossless compression?

when sending something important that has to be clear

When should you use lossy compression?

when you have to send something less important and doesn't matter about quality.