Objective(s):
By the end of this lesson the student will be able to:
Define
these terms: variable;
algebraic expression; signs of operation; order of operations. 
PreClass
Assignment:
Resources/Equipment/Time Required:
Outline:
Algebra provides
the basics for all
higher math. You will work with numbers and letters (variables) to form
sentences (expressions) that you can solve. The best way to learn math
is by practicing it, so each lesson will include exercises using the
skills
learned.
A place to begin:
Letters in math are
called variables.
They can stand for different numbers at different times.
A mathematical
sentence is called
an expression. It can include numbers, variables, signs of operation,
and
symbols of inclusion.
Signs of operation
tell you what
to do to the sentence. The four operations are addition, subtraction,
multiplication,
and division.
Symbols of
inclusion are parentheses
( ) and brackets [ ].
An important caution:
Be very neat in
your calculations.
Many an algebra problem is missed because the student misread what he
or
she had written or did not "line up" the column correctly for
subtraction
or division. Always double check operations. You don't want to miss a
problem
because you added incorrectly.
Let's Get Started:
To "evaluate" an
expression means
to find its value, or to solve it. The first rule to learn about
algebra
is "what to do when." The order in which an expression's operations are
done can completely change the answer.
When evaluating an
algebraic expression,
first look for the symbols which show the innermost work. That can be
expressed
by use of parentheses or brackets. If BOTH parentheses and brackets are
present, the parentheses are usually the innermost and should be worked
first.
Here is an example:
24 + [46  (2 X 11)]
24 + [46  22]
24 + 24
48
Now it's time for
you to try a few.
EXERCISE:
9  (4 X 2)
(9  4) X 2
(9  4) X (2 X 1)
48  [42  (3 X
9)]
63  [8/2 + (14 
10)]
(Note: 8/2 is the same
as 8 divided
by 2, just like in fractions.)
[800/ (200 X
4)]
28 + [ 10  (4 + 2)
]
(115) X (10 +
14)
125 / ( 5 X 5)
(Remember from number
5? / = divided by.)
[28  (4 X 5)]  4
ANSWER KEY, Click
Here:
Assignment(s)
including Answer key: Complete
above
PreRequisite
To: Basic
Algebra
 Lesson 2
Submitted
by: © Elaine
Ernst Schneider is a freelance
writer
and a teacher. She has been writing since high school and has published
articles, songs, and children's work. Presently, Elaine is a curriculum
author for Group Publishing and also writes the City Songs column for
www.newcolonist.com
ezine. 

Feedback
Hi,
I am a grade nine, and I am having exams coming up. I use to have
trouble with many different concepts in class, but because I went
to your math site, I was able to learn a lot of different
things I never knew.
Just wanted to say thanks,
Mari Anne (January, 2005)


For
more Articles by this Consultant, Click
Here
For
more Lesson Plans Grade 9 Algebra, Click
Here
