Variable Expressions2009 SOL A.1

Varina High SchoolTammy Wallace

Vocabulary• A variable is a symbol, usually a letter, used to

represent a quantity. This quantity represents an element of any subset of the real numbers.

• An algebraic expression may contain numbers, variables, operations, and grouping symbols. An algebraic expression may be evaluated by substituting values for the variables in the expression.

How are algebraic expressions used in

Algebra?• Algebraic expressions can be translated to

verbal expressions or word phrases• Verbal expressions or word phrases, which

describe characteristics of given conditions, can also be translated into algebraic expressions for the purpose of evaluation.

In expressions, there are many

different ways to write

multiplication:

1. or

2. x

We are not going to use the multiplication symbol (#5) any more. Why do you think we will not use this anymore?

Division, on the other hand, is written as:

1)

Here are some phrases you may have listed. The terms with * are ones that

are often used.Addition Subtractio

n

Multiplicati

on

Division Exponents

 sum differenc

e

produce quotient power of

___

increase  decrease times divided squared

plus minus multiplie

d

ratio cubed

add subtract  

 

 more than less than

total

Writing Algebraic Expressions

Steps for Writing Algebraic Expressions:

1.Read for understanding

2.Define the variable

3.Translate the words into numbers/variables/operations

4.Write as an expression

Define a variable and write an algebraic expression for each

phrase. two times a number plus 5  

Read for understanding

Define the variable.

Translate to numbers

Write as an expression

two times a number plus 5

This can be whatever you want it to be Let x = “a number”

two times a number plus 5

2 ∙𝑥+5

7 less than three times a number(NOTE: when the words “more than” or “less than”

are used, write the expression opposite than how you read it)

Read for understanding

Define the variable

Translate to numbers

Write as an expression

7 less than 3 times a number

Let x = “a number”

7 less than 3 times a number

( h𝑠𝑜𝑚𝑒𝑡 𝑖𝑛𝑔)−73 ∙ 𝑥

The absolute value of the sum of a number a 5

Read for understanding

Define the variable

Translate to numbers

Write as an expression

the absolute value of the sum of a number and 5

Let x = “a number”

the absolute value of the sum of a number and 5

|?|?+? and

The quotient of a number cubed and 12.

Read for understanding

Define the variable

Translate to numbers

Write as an expression

quotient of a number cubed and 12

Let x = “a number”

quotient of a number cubed and 12

??𝑥

?3𝑎𝑛𝑑12

The square root of the product of 6 and a number squared.

Read for understanding

Define the variable

Translate to numbers

Write as an expression

square root of the product of 6 and a number squared

Let x = “a number”

square root of the product of 6 and a number squared

√?? ∙?6 and

Write an verbal expression for each algebraic expression

 Answers may vary

Write an verbal expression for each algebraic expression

 Answers may vary

Write an verbal expression for each algebraic expression

Answers may vary

Write an verbal expression for each algebraic expression

Answers may vary