The City School Liaquat Campus Class:08 Reinforcement worksheet

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1 The City School Liaquat Campus Class:8 Reinforcement worksheet To begin with A computer understands only two digits: and. With these single digits it is possible to communicate with other computers on the Internet and to store text, images, video, and control peripherals. When the speedometer of a car shows "85 mph" its computer understands the mph! Let's investigate questions The s we understand are decimals while a computer understands binary s. How can we convert a from one format to another? The binary consists of 8 digits (bits). To convert that to a decimal we write the digits in a row and calculate the place value of each digit. Then add only the nonzero place value. The resulting sum is the equivalent decimal. Binary digits Place value 2 7 = = = = = = 4 2 = 2 2 = Decimal = 85 Can you calculate the decimal equivalent of the binary by filling in the blanks in the table below? Binary digits Place value 2 7 = = = = = = 4 2 = 2 2 = Add this decimal to 85. What decimal is obtained? Can you convert this decimal to binary? It may help you to complete the table below. Binary digits Place value 2 7 = = = = = = 4 2 = 2 2 = Decimal = Decimal = How many positive integers can be represented by a binary 'word' of 8-bit? If it seems difficult to convert a positive integer to binary then you can follow the method of successive remainders. According to this: We divide the decimal by 2. The result shall be divided by 2 again, the new quotient again by 2, etc., until we find the quotient. We write the remainders of these divisions in reverse order

2 For example, let's calculate the binary of 43. The rightmost digit in the row of the binary The binary of 43 is. It includes only six digits. If we want 8 digits then we must addzeroes to the left (i.e. = ). Now can you calculate the binary of 85 using this method? Let s discover Hexadecimal s are used to limit the area over which a series of binary digits can exist. The following table shows the correlation between hexadecimal digits and decimal s. Hexadecimal digits Decimal assignment A B C D E F Converting a hexadecimal to a decimal is the same process by which we convert a binary to decimal. Thus for example, the hexadecimal 3AD is equal to the decimal 94. Hexadecimal digits 3 A D Decimal assignment 3 3 Place value 6 2 = = 6 6 = 3*256 *6 3* Decimal = 94 Now, convert the hexadecimal 2A3 to a decimal by filling in the table below. Hexadecimal digits 2 Α 3 Decimal assignment Place value 6 3 = = = 6 6 = Decimal = The rightmost digit in the row of the hexadecimal

3 To convert a decimal to hexadecimal, follow the method of successive balance. So, can you find which hexadecimal corresponds to the decimal 234? What hexadecimal did you find? Let s develop and implement All data types (text, images, etc.) are stored in the form of binary s. The ASCII character set was one of the first to be applied for assigning a character to a. The RGB model assigns a color to a. Consult the table in your book (p. 9) that maps the position of each character in the ASCII and find the 8-bit binary s and the hexadecimal equivalent to the capital letters S and O. ASCII character S O 8-bit binary Hexadecimal Open Windows Calculator and determine whether you have found the correct s above (see p. 8). Let s develop and implement The computer makes calculations using proper connection of gates (p. ). Three of them (AND, OR and XOR) are with two signal inputs, while the NOT gate has one input. What acts can they do and how? Let's take two binary s A and B of -bit each. Input A will take the values or, like B. To add them, we know that; Decimal system Binary system Α Β C + = + = + = + = + = + = + = 2 + = Note that the binary sum C is a 2-bit. Therefore, if we have two inputs (A and B), we will need two outputs for C; the C (right figure C) and C2 (left figure C). The adjacent truth table defines the above addition. Α Β C2 C C In the figure below in each rectangle, draw the appropriate gate so that the circuit implements the truth table. Α Β C C2

4 Match each sentence on the left column with the correct component on the right The ALU performs arithmetic and logical operations on all required data. It carries out instructions and also performs the operations on various registers. If it is necessary to get more data for a specific instruction, then they are transferred from the main memory to the registers. Executing of instructions The results of executing instructions are placed in the main memory. Decoding of instructions The instructions are transferred from the main memory and stored temporarily in small memories within the CPU called registers. The control unit interprets the instruction stored in the instruction register, turning it into a signal that can be understood by the ALU. Storing of results Fetching of instructions How is packet switching implemented?fill in the blanks with the correct word or phrase in the table. are divided into Destination individually to their Messages Packets reassembled in their transferred through the How do computers identify web pages on the Internet? Fill the blanks with the correct word or phrase in the table. computer DNS Hostname is a for a IP address URL web page

5 Without protocols there would not be communication Network Protocol is a set of rules that defines how data is formatted and processed on a network in order to exchange messages among the devices of the network. Protocol stack is a set of network protocol layers that work together. Each protocol layer consists of one or more protocol modules that communicate with two others; the higher and the lower of its layer. The lowest layer handles the hardware while the highest handles user applications. The following figure shows the layers hierarchy and structure TCP/IP Suite Application Layer HTTPS HTTP FTP SMPT DNS Audio Codecs RTP/RTCP Video Codecs Transport Layer Transmission Control Protocol (TCP) User Datagram Protocol (UDP) Internet Layer Internet Protocol (IP) Network Interface Layer Ethernet, Wireless, Cable, Fiberglass Consult your book on the functioning of the various protocols. Match each text with the correct layer. This layer splits data in order to be sent in packets and reorders and reassembles the packets at their destination. It deals with any errors that occur, such as if a packet never arrives at the destination or the contents of a packet are corrupted. This layer provides the user a way to access any information in the network through an application. This layer is responsible for routing data packets between different networks, regardless of their infrastructure. Let's investigate Personal data is any piece of information relating to you. If you have control of your personal data then you have control your personal life, too.but what is personal data and how could it be used against you? The table below shows different types of personal data. Evaluate these types of data on a scale from A to C: Information that should not be published should be graded A. Information you choose for some people to know should be graded B. Information you do not mind the whole world knowing should be graded C. Personal data. Your name 2. Your address 3. Your musical tastes 4. Your 5. Your phone s 6. Your favorite movies 7. Your various passwords 8. Your credit card s 9. Your school. Photos of You Grade

6 . Videos of You 2. Your school grades 3. Your age 4. Your nickname Module 2 Relationships between tables Your team has taken over the management of the school library. Your responsibility is to record the books that students borrow and to make sure they are returned. A basic database table (Students) is that which contains the main information about students, such as their First name, Last name, Phone, Home address and address. In this table have inserted the following records: First name Last name Phone Home address address Tom Smith Greenville tom@digital-kids.com George Smith Greenville tom@digital-kids.com Stella Williams Newton Ave. stella@digital-kids.com Alex Johnson Central Ave. alex@digital-kids.com Tom Brown CastleCourt tbrown@digital-kids.com The first row of the table contains the field names. The rest of the rows are the records of the table. We consider as Primary Key the field whose value uniquely identifies the record. Namely, it is impossible for this value to appear in two or more records. Which field of this table could be Primary Key? Justify your answer. Observe the following table. Student_ID First name Last name Phone Home address address Tom Smith Greenville tom@digital-kids.com 2 George Smith Greenville tom@digital-kids.com 3 Stella Williams Newton Ave. stella@digital-kids.com 4 Alex Johnson Central Ave. alex@digital-kids.com 5 Tom Brown CastleCourt tbrown@digital-kids.com Which field of this table could be Primary Key? Justify your answer. The structure of the table Students, namely the fields names of each record, is depicted to the adjoining picture. Now, let s divide this table into two separate tables. The first (Students_Names) contains only the students names. The second (Students_Info) contains the rest contact information. Fill in the empty cells so that each record of the first table is matched with one record of the other table (and even the correct one). Students_Names Student_ID First name Last name Smith 2 George 3 4 Alex Johnson 5 Tom Students_Info Student_ID Phone Home address address Greenville tom@digital-kids.com 567 Central Ave tom@digital-kids.com CastleCourt

7 These twotablesare relatedas shown in thefollowing picture. Now, let s create a table (Books_Authors) with the available book titles of the school library and their authors. In this table we inserted some records. Author name Book Title Charles Dickens Great Expectations Fyodor Dostoevsky Crime and Punishment Fyodor Dostoevsky The Idiot Hans Christian Andersen Fairy tales Charles Dickens The Battle of Life Ernest Hemingway The Old Man and the Sea Observe the table above and answer the following questions. Put a if the sentence is correct There is a book title written by two (or more) authors. There are authors who have written only one book title. There are authors who have written two (or more) book titles. Only one book title corresponds with each author. Only one author corresponds with each book title. For each author there could be many corresponding book titles. Now, let s divide this table into two separate tables. The first table (Authors) contains the authors (4 records) and the second table (Books) contains the book titles (6 records). In each table we add a Primary key. More specifically, in the table Authors we add the Author_ID, as in the Book_ID in the table Books. As the table Books contains more records than the table Authors does, we add one more field (the Author_ID) in the table Books, which shows the book s author. We name this field as Secondary key. Fill in the empty cells of the following tables. Authors Author_ID Author name Books Book_ID Book title Author_ID These two tables are related as shown in the following picture.

8 Now, we create a table that contains information about the library books. This table should contain the name of the student, the book title, the date borrowed and the date returned. We insert some records about some students: First name Last name Book title Date borrowed Date returned Stella Williams The Battle of Life 4/3/23 George Smith The Idiot 4/25/23 5/3/23 Alex Johnson Fairy tales 4/28/23 5/3/23 Tom Brown The Idiot 5/6/23 George Smith Crime and Punishment 5/2/23 6/4/23 Observe the table above and answer the following questions. But in this table there is information that has already been inserted into tables that have been created. Find this information and answer the following questions. Select the correct answer The fields Firstname and Lastname of each student are in the table The field Booktitle is in the table The fields Date borrowed and Datereturned are in the table Students_Names Students_Info Books Authors None Students_Names Students_Info Books Authors None Students_Names Students_Info Books Authors None Now, we create a new table again for lending books (Books_Lending) and fill it with information. This table has its own primary key, so each lending will have a certain code. Then fill the empty cells of the following table. Keep in mind that when you add a book or a student id the database will retrieve all the necessary information through the related tables (relationships). Books_Lending Lend_ID Student_ID Book_ID Date borrowed Date returned 4/3/23 2 4/25/23 5/3/23 3 4/28/23 5/3/23 4 5/6/23 5 5/2/23 6/4/23 All the tables you created are shown in the figure below.