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 everything covered both in
Pre-Algebra and in more complicated mathematics. It is impossible to master
the complex principles of Pre-Algebra without first mastering the operations
and their properties.

You are probably used to working with the four basic operations, but there are
some things about these operations that you may not know. In particular, these
operations have certain properties that can make evaluating complex
expressions a lot easier.

The first section will explain how to correctly evaluate a
complicated expression using the Order of Operations,
which specifies the order in which to carry out operations when evaluating an
expression. The Order of Operations is important to know; if you do not follow
it correctly and instead carry out the operations in the incorrect order,
your answer will also be incorrect.

Section two will teach some properties
of addition that will make it easier to evaluate an expression without
depending on a calculator. These properties are the Commutative
Property, the Associative Property, and the
Identity Property.

The third section will teach some
properties of multiplication. Like addition, multiplication has its own
version of the Commutative Property, the Associative Property, and the Identity
Property. Multiplication has two additional properties--the Zero Product
Property and the Distributive Property.

The fourth and final section will
discuss inverse operations, which "reverse" other operations. These will
be especially useful for future algebra.

Each section will teach something about basic operations that will help you
evaluate expressions correctly and easily. These properties will also be
useful when you approach more difficult topics in pre-algebra, such as
solving an algebraic equation for a variable.