Lesson One TEXT What is a Computer A computer is a machine that takes in information
and processes that data in some way. The data may be number,
letters, pictures, or even sounds. The computer can perform arithmetcial
operations, for example, addition, subtraction, multiplication,
division and power. All higher mathematical problems are reduced to
thesesimple operations before being solved. The computer can compare
statements. After a computer tests two statements, it can make a decision
about which statement is true. Thsi basic ability has made possible
many of the successful applications of computers today. The computer
are programmable. Programs are written to give istructions to the computer.
Some of programs used to operate the computer are stored inside the computer.
People who operate the computer never see the actual programming.
Other programs are written by students and professional programmers.
Most of the computers used today are digital computers, from small
home computer systems to the large systems that the government uses to
handle data about the entire nation. A computer is a data processing machine.
Data flow into the machine as input. Information flows from the machine as output.
The compjuter processes the data. What do we mean when we say that a computer processes data?
We processironore to make steel; we process wood pulp to make paper.
'Process' implies that a change takes place, that the raw materals are in
some way restructured or manipulated. Often, data processing involves filtering and
summarizing data so that underlying patterns can be perceived. How
does a computer process its data? What functions, what operations,
can it perform? Generally, computers can add, substact, multiply, divide,
compare, copy, request input, and request output. So can most pocket calculators.