The Number Line
Number Lines
We can arrange all the whole numbers on a number line. A number line is a horizontal line that has
points, equally spaced, which correspond to each of the whole numbers:
Figure %: Whole Number Line
Each number is greater than
Percents
Percents
A percent employs a percent sign (%) followed by a number. It looks like this: 23%. A percent
represents a fraction in which the number to the left of the % sign is the numerator and 100 is the
denominator. "Percent" means "parts per hun
Terms
Absolute Value - (Positive) distance between a number and zero on the number line; the
corresponding "unsigned" number. | - 4| = 4 and | 4| = 4.
Counting Numbers - Also called natural numbers, the set of positive numbers used to count
objects. 1, 2,
Properties of Multiplication
In the last section, we learned how to add long strings of numbers using the properties of addition.
Similarly, it is sometimes necessary to multiply long strings of numbers without a calculator; this task
is made easier by le
Operations with Negative Numbers
Subtracting a Larger Number from a Smaller Number
It is easy to compute 6 - 4 = 2 and 14 - 5 = 9, because the answers are positive. But how would one
compute 4 - 6? On the number line, moving to the left is equivalent to s
PREALGEBRA: OPERATIONS (SECTION ONE)
Order of Operations
An expression represents a number. For example, 6 - 2 is an expression that represents the number
4, and 35 is an expression that represents the number 15. This section will discuss how to find the
Classification of Numbers
As you could see in the last section, with its various number lines, there are a number of different
ways to classify numbers. In fact, there are even more ways to classify numbers than last section
displayed. This section will r
Properties of Addition
Sometimes it is necessary to add long strings of numbers without a calculator. For example, one
might be asked to find 48 + 33 + 52 + 11 + 17 . This sum is difficult to compute without a calculator,
but the task can be made a lot ea
Absolute Value
Absolute Value
The absolute value of a number, denoted by vertical lines surrounding the number, is the positive
distance between the number and zero on the number line. It is the value of the corresponding
"unsigned" number-either itself o
Inverse Operations
An inverse operation "reverses" another operation. Addition and subtraction are inverses of each
other because adding and subtracting the same number does not change the original number. For
example: 7 - 6 + 6 = 7 and 13 + 11 - 11 = 13.
PREALGEBRA: OPERATIONS
Introduction and Summary
Almost all of mathematics involves the use of the four basic mathematical operations-addition,
subtraction, multiplication, and division. Understanding these basic mathematical operations is
crucial to every