Download Expressions

Objective
The student will be able to:
translate verbal expressions into
math expressions and vice versa.
SOL: A.1
What is the area of a rectangle?
Length times Width
If the length is 3 meters and the width is 2
meters, what is the area?
A=LxW
A = 3 x 2 = 6 meters2
A, L and W are the variables. It is any
letter that represents an unknown number.
An algebraic expression
contains:
1) one or more numbers or variables, and
2) one or more arithmetic operations.
Examples:
x-3
3 • 2n
4
1
m
In expressions, there are many
different ways to write multiplication.
1)
2)
3)
4)
5)
ab
a•b
a(b) or (a)b
(a)(b)
axb
We are not going to use the multiplication symbol
any more. Why?
Division, on the other hand, is
written as:
x
1)
3
2) x ÷ 3
Throughout this year, you will hear many
words that mean addition, subtraction,
multiplication, division, and equal to.
Complete the table with as many words as
you know.
Addition
Subtraction
Multiplication
Division
Equals
Here are some phrases you may have listed.
The terms with * are ones that are often
used.
Addition
Subtraction Multiplication Division
Equals
•Plus *
•And
•Added to
•Greater than
•More than
•Increased by
•Total
•Sum of
•Minus
•Difference
between
•From
•Less
•Less than
•Fewer than
•Decreased by
•Take away
•Is
•Is the same as
•Gives
•Will be
•Was
•Is equivalent
to
•Times
•Product
•Double
•Triple
•Twice
•Quotient of
•Half of
•Goes into
•per
Write an algebraic expression for
1) m increased by 5.
2) 7 times the product of x and t.
3) 11 less than 4 times a number.
4) two more than 6 times a number.
5) the quotient of a number and 12.
Which of the following expressions represents
7 times a number decreased by 13?
1.
2.
3.
4.
7x + 13
7x - 13
13 - 7x
13 + 7x
Write down your answer now!
Which of the following expressions represents
7 times a number decreased by 13?
1.
2.
3.
4.
7x + 13
7x - 13
13 - 7x
13 + 7x
Did you get the
right answer?
Which one of the following expressions
represents 28 less than three times a
number?
1.
2.
3.
4.
28 - 3x
3x - 28
28 + 3x
3x + 28
• Write down your answer now!
Which one of the following expressions
represents 28 less than three times a number?
1.
2.
3.
4.
28 - 3x
3x - 28
28 + 3x
3x + 28
How did you do?
Write a verbal expression for:
1) 8 + a.
2) m
r
.
Which of the following verbal
expressions represents 2x + 9?
1.
2.
3.
4.
9 increased by twice a number
a number increased by nine
twice a number decreased by 9
9 less than twice a number
Which of the following verbal expressions
represents 2x + 9?
1.
2.
3.
4.
9 increased by twice a number
a number increased by nine
twice a number decreased by 9
9 less than twice a number
Did you get it?
Which of the following
expressions represents the sum of
16 and five times a number?
1.
2.
3.
4.
5x - 16
16x + 5
16 + 5x
16 - 5x
Which of the following expressions represents
the sum of 16 and five times a number?
1.
2.
3.
4.
5x - 16
16x + 5
16 + 5x
16 - 5x
Any questions?
When looking at the expression
103, 10 is called the
base
and 3 is called the
exponent or power.
103 means 10 • 10 • 10
103 = 1000
How is it said?
21
Two to the first power
22
Two to the second power or two squared
23
Two to the third power or two cubed
2n7
Two times n to the seventh power
Which of the following verbal expressions
represents x2 + 2x?
1.
2.
3.
4.
the sum of a number squared and
twice a number
the sum of a number and twice the
number
twice a number less than the number
squared
the sum of a number and twice the
number squared
Answer Now
Which of the following expressions
represents four less than the cube of a
number?
3
1. 4 – x
2. 4 – 3x
3. 3x – 4
4. x3 – 4
Answer Now
Evaluate.
21
2
22
2•2=4
23
2•2•2=8
2n7
We can’t evaluate because we don’t
know what n equals to!!
Is 35 the same as 53?
Evaluate each and find out!
35 = 3 • 3 • 3 • 3 • 3 = 243
53 = 5 • 5 • 5 = 125
243 ≠ 125
They are not the same!