Ap Computer Science Principle Code.org Unit 1 Chapter 1

This statement is always true because when I put the binary pattern into my calculator, it continued to come out as 65 after 5 trails with the programmer calculator.

"The binary pattern 01000001 represents the number 65." Write a brief response explaining whether you believe this statement is always true. Explain your reasoning.

A. 9 bits

8 bits is enough to represent 256 different numbers. How many total bits do you need to represent 512 (twice as many) numbers? A. 9 bits B. 10 bits C. 16 bits D. 17 bits

B. AABB

A binary message consisting of four bits was sent to you by a friend. The message was supposed to be ABAB. Unfortunately, your friend set the bit on the wire once every 2 seconds, but you read the wire once every second. Assuming that the first bit was sent and read at the same time, what message did you receive instead? A. ABAB B. AABB C. AAAA D. BBBB E. ABBB

You will need the seconds.

A binary message was recorded as a wave as shown in the image below. Can you decode the message? Explain what information you would need in order to successfully decode the message into A's and B's. https://images.code.org/c8ba0db14fabb778dc034ac4656259fa-image-1434429617999.png

D. A question which can be answered in only one of two possible ways

A binary question is defined as: A. A piece of information that is sent in pairs B, Two questions which share the same answer C. A message which has two possible states D. A question which can be answered in only one of two possible ways

Bit

A contraction of "Binary Digit". A bit is the single unit of information in a computer, typically represented as a 0 or 1.

Binary Message

A message that can only be one of two possible values.

A. Add a bit to studentID to double the number of IDs that the database can represent.

A middle school is expanding to open a high school next year, doubling the total number of students. The school keeps a database in which each student's unique ID number is stored as an 8 bit number called studentID. Before the arrival of the new students almost every 8 bit number has already been assigned to a student. Which is the most accurate description of how the school could modify the way studentID is represented in the database to ensure each incoming student receives a unique ID? A. Add a bit to studentID to double the number of IDs that the database can represent. B. Double the number of bits in studentID to double the number of IDs that the databases can represent. C. Keep using an 8-bit number for studentID but reserve the first bit to indicate middle school or high school. D. Remove a bit from studentID to make room for incoming students.

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.

Binary Question

A question to which there are only two possible answers.

Protocol

A set of rules governing the exchange or transmission of data between devices.

D. Low bandwidth, low latency

A user clicks on a website, and it begins to load immediately, but it takes a long time to load completely and pictures appear slowly, one by one. Which of the following is demonstrated through this situation? A. High bandwidth, high latency B. Low bandwidth, high latency C. High bandwidth, low latency D. Low bandwidth, low latency

C. 2^32 times as many values can be represented.

A video-streaming Web site uses 32-bit integers to count the number of times each video has been played. In anticipation of some videos being played more times than can be represented with 32 bits, the Web site is planning to change to 64-bit integers for the counter. Which of the following best describes the result of using 64-bit integers instead of 32-bit integers? A. 2 times as many values can be represented . B. 32 times as many values can be represented. C. 2^32 times as many values can be represented. D. 32^2 times as many values can be represented.

Binary

A way of representing information using only two options.

ASCII

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

Decimal numbers were used to represent the complexity of the binary number system. Decimal numbers were helpful in designing a system to represent in bits because you didn't have to write out the numbers in binary.

An abstraction is a simplified representation of something that is more complex. Decimal numbers were a useful abstraction in the context of today's lesson. Write a short response to both questions below. What is the underlying complexity decimal numbers were used to represent. How were decimal numbers helpful in designing a system to represent text in bits?

8

If you just had two shapes (say, a circle and a square), how many 3-place patterns could you make?

1. copper wire = electric voltage 2. Radio Wave= alternative frequencies 3. Fiber Optic Cable= beam of light

Match the bit sending technology with the underlying system 1. Copper Wire 2. Radio Wave 3. Fiber Optic Cable a.Alternating frequencies b. Beam of light c. electric voltage

C. V

The next question refers to hexadecimal which is a base-16 number system - a number system that uses one of 16 possible digits for each place value. ASCII is a character-encoding scheme that uses a numeric value to represent each character. For example, the uppercase letter "G" is represented by the decimal (base 10) value 71. A partial list of characters and their corresponding ASCII values are shown in the table below. Decimal ASCII 80 P 81 Q 82 R 83 S 84 T 85 U 86 V 87 W 88 X 89 Y 90 Z A. A B. L C. V D. Y

B. 1010

What is the 4-bit number for the decimal number ten (10)? A. 0010 B. 1010 C. 0110 D. 0101

5bits

What is the minimum number of bits you need to encode the 26 letters of the alphabet plus a space?

C. 5 bits

What is the minimum number of bits you would need to encode the 26 letters of the alphabet plus a space - a total of 27 characters? A. 2 bits B. 3 bits C. 5 bits D. 6 bits

Bit Rate

the number of bits that are conveyed or processed per unit of time. e.g. 8 bits/sec.

code

to write code, or to write instructions for a computer.

B. DEC: 13, BIN: 1110, HEX: F

Consider the following numbers given in Binary (BIN), Decimal (DEC), and Hexadecimal (HEX) representations: BIN: 1110 DEC: 13 HEX: F Which of the following lists the numbers in order from least to greatest? A. BIN: 1110, DEC: 13, HEX: F B. DEC: 13, BIN: 1110, HEX: F C. DEC: 13, HEX: F, BIN: 1110 D. HEX: F, DEC: 13, BIN: 1110

Bandwidth

Transmission capacity measure by bit rate

24 bits

How many bits? ASCII has an encoding for every character of the alphabet as well as encodings for numbers -- that is, encodings for the symbols of the digits 0-9. So here is a trick question: How many bits are required to store the text of the number "150" in ASCII?'

It is important to have rules in a numbering system because all the numbers can be in a orderly fashion in which to count off correctly. If we didn't have a proper number system we wouldn't be as advanced as we are in modern day society.

In 50 words or less, describe the concept of a number system. Why are rules required for a number system to be useful?

D. There is a limit to the number of things that can be represented in binary data at which point switching to hexadecimal representation is necessary.

The next questions refers to the hexidecimal (base 16) number system: Number bases, including binary, decimal, and hexadecimal, are used to view and represent digital data. Which of the following is NOT true about representing digital data? A. At one of the lowest levels of abstraction, all digital data can be represented in binary using only combinations of the digits zero and one. B. Hexadecimal is used to represent digital data because hexadecimal representation uses only 1 digit to represent groups of 4 binary digits. C. Binary can be used to represent more complex, higher level abstractions, including but not limited to numbers, characters, and colors. D. There is a limit to the number of things that can be represented in binary data at which point switching to hexadecimal representation is necessary.

7 bits

The standard QWERTY keyboard has 47 keys that can place characters on the screen. Each of these keys can also display a second character by holding the "Shift" key at the same time. How many bits would you need to encode everything that could be typed on this keyboard?

Latency

Time it takes for a bit to travel from its sender to its receiver.

D. It's easier, cheaper, and more reliable to build machines and devices that only have to distinguish between binary states.

What is the best explanation for digital data is represented in computers in binary? A. The binary number system is the only number system flexible enough to allow for representing data other than numbers. B. As a consequence of history: early pioneers of computing were making secret codes in binary, and this simply evolved into modern computing. C. It's impossible to build a computer machine that uses anything but binary to represent numbers. D. It's easier, cheaper, and more reliable to build machines and devices that only have to distinguish between binary states.

2 bits

When responding to a question with 4 choices, the most efficient method will require _____ number of bits.

14

You have a coordinate grid that is 96 x 96. Assuming that you encode the x and y coordinate as separate numbers, what is the minimum number of bits that you will need to encode a coordinate in that space?

Abstraction

a simplified representation of something more complex. Abstractions allow you to hide details to help you manage complexity, focus on relevant concepts, and reason about problems at a higher level.