Commodore 64 User Manual page 37

NUMBER KEYS
The number keys are found in the row above
the letter keys. Not only do you use these
keys to type any numbers needed in a mes
sage, but you use the number keys for the fol
lowing purposes:
• To perform mathematical functions
• To begin each line when creating your own
programs
• To type the punctuation that appears on the
top half of the number keys
• To change the color of text on the screen
In the next series of exercises, you will learn to
use the number keys for each of these
purposes.
An important thing to remember: On your
computer, the numbers 1 and 0 (one and zero)
are not interchangeable with the letters I or I
(lowercase L and uppercase I) and O [upper
case O). If you use these letters instead of the
numbers, the computer will become confused,
and it will not be able to perform your
instructions.
PERFORMING MATHEMATICAL
FUNCTIONS USING NUMBERS AND
SYMBOLS
Recall that one of your computer's primary
functions is to calculate. This means that your
computer can add, subtract, multiply, and
divide, as well as perform other, more complex
mathematical functions.
First you tell your computer to print the
answer on the screen for you, either by typing
the word PRINT or by pressing the QUESTION
MARK/SLASH key [with the SHIFT key held
down). Then you type the desired mathemat
ical equation. When you are ready for the cal
culation to begin, you press the RETURN
key—not the - [equals sign) key. Try per
forming a few simple equations on your com
puter now.
NUMBER keys
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