additive inverse add up to 0); and, finally, it is the starting point in measurements. The
zero symbol is also called a cipher (no relation to sending secret messages) or the
symbol for the absence of quantity (although be aware that cipher can also mean any
Hindu-Arabic numeral). In other words, zero is naught (nothing, or, from the Old
English, na ̄ wiht,meaning “not” [na] and “thing” [wiht]).
Mathematicians also use the word non-zeroto represent a quantity that does not
equal zero. A real non-zero number must either be positive or negative; a complex
non-zero number can be the real or imaginary part of the equation. (For more infor-
mation about complex numbers, see above.)
What is an indeterminate number?
As with many other fields, mathematics has terms that are sometimes confusing or
overlapping. For example, it is interesting to note that there issuch a number as 0/0,
which is called an indeterminatenumber. But be careful: This is not the same as an
undefined number. If an indeterminate number comes up somewhere, you never
know the value for your specific case—and you can conceivably give it any number of
values. Confusing? Don’t worry, you’re not alone. It is one of those quandaries that
often baffles the best mathematicians.
BASIC MATHEMATICAL OPERATIONS
What does an equal signrepresent?
In standard arithmetic terms, the equal sign () is a symbol that represents two
amounts with the same value. For example 7 7; or 3 4 7. When something is
not equal, the sign is , as in 2 3 or 3 7 12.
In a line of computer code, the equal sign can mean something much different.
For example, for codes used under certain conditions, such as a JavaScript-reading
computer, a single equal sign in a line of script means “is”. There is even a double
equal sign () that means “is equal to,” an important difference when writing code
for the computer. In addition—and confusing as it may seem—the computer codes for
“not equal” are different, and include !and /.
What is addition?
Addition is an operation in which two numbers, called the addends,produce a third
number called the sum. Natural numbers are added by starting with the first addend
and counting as many more numbers as the second addend. For example, for 2 4,
you would think 2, 3 (as the first number after 2), 4 (as the second number), 5 (as the
third number), and 6 (as the fourth number), thus the numbers add up to 6. Not all
numbers are added in the same way as natural numbers. 91