2 Easy Algebra Step-by-Step
Likewise, 844 = 2 is a natural number,
but 83 is not.
When you include the number 0 with the
set of natural numbers, you have the set of
whole numbers:W = (^) {}^01 ,,,,^223453 ,,,,,^5676788 ...
If you add or multiply any two whole numbers, your result is always a
whole number, but if you subtract or divide two whole numbers, you are not
guaranteed to get a whole number as the answer.
Like the natural numbers, you can represent the whole numbers as
equally spaced points on a number line, increasing endlessly in the direction
of the arrow, as shown in Figure 1.2.
The graph of a number is the point on the number line that corre-
sponds to the number, and the number is the coordinate of the point. You
graph a set of numbers by marking a large dot at each point corresponding
to one of the numbers. The graph of the numbers 2, 3, and 7 is shown in
Figure 1.3.
On the number line shown in Figure 1.4, the point 1 unit to the left of
0 corresponds to the number − 1 (read “negative one”), the point 2 units to
the left of 0 corresponds to the number −2, the point 3 units to the left of 0
corresponds to the number − 3 , and so on. The number − 1 is the opposite of
1, − 2 is the opposite of 2, − 3 is the opposite of 3, and so on. The number 0
is its own opposite.
A number and its opposite are exactly the same distance from 0. For
instance, 3 and − 3 are opposites, and each is 3 units from 0.
The number 0 is a whole number,
but not a natural number.
Figure 1.2 Whole numbers
041 2 385 67
You do not get a natural number as the
quotient when you divide natural numbers
that do not divide evenly.
Figure 1.3 Graph of 2, 3, and 7
041 2 385 67