Find the answers to these questions after quickly reading the text

1.  What is a fraction?

2. What are the elements of a fraction?

 

4. Read and translate the text.

The word fraction is derived from the Latin word fractio, which means to break.

A fraction describes how many parts of a certain size there are, for example, one-half, eight-fifths, three-quarters. A fraction is the indicated quotient of two expressions. The quotient is usually indicated by the form a/b, which means a divided by b.

A common, vulgar, or simple fraction consists of an integer numerator displayed above a line (or before a slash), and a non-zero integer denominator, displayed below (or after) that line. Numerators and denominators are also used in fractions that are not common, including compound fractions, complex fractions, negative, proper, improper and mixed.

The numerator of a fraction is the dividend and the denominator is the divisor. The numerator represents a number of equal parts, and the denominator, which cannot be zero, indicates how many of those parts make up a unit or a whole.

Fractions in algebra have in general the same properties as fractions in arithmetic. For example: in arithmetic 8/12 = 2/3; in algebra 5ax/5ay = x/y. A fraction in its lowest terms is a fraction whose numerator and denominator have no common factor.

To reduce a fraction to its lowest terms, the rule is the same as in arithmetic: we resolve the numerator and denominator by the factors common to both. In this sense the word cancel is understood to mean the process of dividing the numerator and denominator by the factor common to both.

 

Find in the text English equivalents for the following Russian words and word combinations.

делимое, делитель, числитель, знаменатель, частное, общий множитель, свойства, выражение, деление, раскладывать (разлагать), сокращать.

TEXT 3B

What is inside a PC system?

Learn the following active words and word combinations.

execute – исполнять

to take place –происходить

control unit – контрольный блок

arithmetic logic unit – арифметическо-логическое устройство

register – регистр

to store – сохранять

performance – производительность

to measure – измерять

volatile – неустойчивый

circuit board – монтажная плата

bus – шина

capabilities – возможности

expansion- расширение

Give the Russian equivalents for the following words and expressions from the text.

nerve center, activities, silicon, to examine, instruction, to interpret, to keep track, speed, system clock, to transfer, communication, extra, motherboard, width.

 

Find the answers to these questions after quickly reading the text.

1.What are the main parts of the CPU?

2. How much is one gigahertz?

 

Read and translate the text.

Processing

The nerve centre of a PC is the processor, the CPU, or central processing unit. This is built into a single chip which executes program instructions and coordinates the activities that take place within the computer system. The chip itself is a small piece of silicon with a complex electrical circuit called an integrated circuit.

The processor consists of three main parts:

The control unit examines the instructions in the user’s program, interprets the instruction and causes the circuits, and the rest of the components – monitor, disk, driver, etc – to execute the functions specified.

The arithmetic logic unit (ALU) performs mathematical calculations (+,–, etc.) and logical operations (AND, OR, NOT).

The registers are high-speed units of memory used to store and control data. One of the registers (the program counter, or PC) keeps track of the next instructions to be performed in the main memory. The other (the instruction register or R) holds the instruction that is executed.

The power and performance of a computer is partly determined by the speed of its processor. A system clock sends out signals at fixed intervals to measure and synchronize the flow of data. Clock speed is measured in gigahertz (GHz). For example, a CPU running at 4GHz (four thousand million hertz, or cycles, per second) will enable your PC to handle the most demanding applications.

RAM and ROM

The programs and data which pass through the processor must be loaded into the main memory in order to be processed. Therefore, when the user runs a program, the CPU looks for it on the hard disk and transfers a copy into the RAM chips. RAM (random access memory) is volatile – that is its information is lost when the computer is turned off. However, ROM (read only memory) is non-volatile, containing instructions and routines for the basic operations of the CPU. The BIOS (basic input/output system) uses ROM to control communication with peripherals.

RAM capacity can be expanded by adding extra chips, usually contained in small circuit boards called dual in-line memory modules (DIMMs).

Buses and cards

The main circuit board inside your system is called the motherboard and contains the processor, the memory chips, expansions slots, and controllers for peripherals, connected by buses – electrical channels which allow devices inside the computer to communicate with each other. For example, the front side bus carries all data that passes from the CPU to other devices.

The size of a bus, called bus width, determines how much data can be transmitted. It can be compared to the number of lanes on a motorway – the larger the width, the more data can travel along the bus. For example, a 64-bit bus can transmit 64 bits of data.

Expansion slots allow users to install expansion cards, adding features like sound, memory and network capabilities.

Find in the text English equivalents for the following Russian words and word combinations.

неустойчивый, шина, исполнять, измерять, производительность, возможности, расширение, регистр, происходить, монтажная плата.

 

Unit 4

TEXT 4A

Addition and Subtraction