Multiplication involves using the * symbol, and division, the / ;

PRINT 12*9 RETURN

PRINT 25/2 RETURN

Basic contains many other arithmetic functions which can be used to find

things like the square root of a number, or calculate its logarithm. Try typing:

PRINT SQR(9) RETURN

PRINT LOG (75) RETURN

If you intend to use your computer mainly for carrying out many complex

calculations, you may find your needs are better met by ViewSheet, which is

available from Acorn software dealers.

The screen is looking rather cluttered now, so type:

CLS RETURN

which is the BASIC instruction to clear the screen.

You have been giving commands which the computer obeys immediately. More

commonly, you will give the computer a series of numbered instructions to

obey. These instructions are stored in the memory and are called the program.

The computer only obeys program instructions when you want it to do so.

You can see the difference between the methods of giving instructions by

typing:

10 PRINT "Hello'' RETURN

This time nothing happens and the > prompt reappears.

At the start of the line you typed the number 10. This is called a line number,

and it tells the computer that the statement which follows is not to be obeyed

immediately. Instead the line is stored in the memory, as you can see by typing:

LIST RETURN

Your one-line program is listed on the screen. You can make the computer

carry out or 'execute' this very short program by typing:

RUN RETURN

Once the computer finishes executing the program, the > prompt returns to

the screen. This shows that the computer is ready to accept further commands

at the keyboard. The program is still stored in memory, as you can confirm by

typing:

LIST RETURN

C 2