1. Writing Algebraic Expressions
Objective:
Be able to write an algebraic expression for a word phrase or write a word phrase for an expression.

2. Although they are closely related, a Great Dane weighs about 40 times as much as a Chihuahua.
An expression for the weight of the Great Dane could be 40c, where c is the weight of the Chihuahua.
When solving real-world problems, you will need to translate words, or verbal expressions, into algebraic expressions.

3. Notes
In order to translate a word phrase into an algebraic expression, let’s review some key word phrases for the basic operations.

4. Review: Definitions
Algebraic expression – an expression that contains at least one variable, operation, and constant
m + 8
r – 3

5. Review: Definitions A constant is a number that does not change.
A coefficient is a number multiplied or divided by a variable.
6x + 5
6 is the coefficient, x is the variable, and 5 is the constant.

6. On your notes, you have this chart, fill it in based on the phrases below in your notes
Addition
Subtraction
Multiplication
Division

7. Here’s mine. Make your corrections
Addition
More than Increase by
Greater than Add
Total Plus
Sum
Subtraction
Decreased by Take away
Difference between Less
Subtract Less than
Subtract from*
Multiplication
Product Times
Multiply Triple
Twice or double Of
Division
Quotient
Divide
Divided By
Split Equally

8. Notes
Multiplication expressions should be written in side-by-side form, with the number always in front of the variable.
3a t c f

9. Notes
Division expressions should be written using the fraction bar instead of the traditional division sign.

10. Examples Addition phrases: 3 more than x x + 3
the sum of 10 and a number c
10 + c
a number n increased by 4.5
n + 4.5

11. Examples Subtraction phrases: a number t decreased by 4 t - 4
the difference between 10 and a number y
10 - y
6 less than a number z
z - 6

12. Examples Multiplication phrases: the product of 3 and a number t 3t
twice the number x 2x
4.2 times a number e
4.2e

13. Examples Division phrases: the number y divided by 2 y / 2
the quotient of 25 and a number b
25 / b
the number y divided by 2
y / 2
2.5 divide g
2.5 / g

14. Write an Algebraic Expression for These Situations
Scott’s brother is 2 years younger than Scott
s - 2

15. Write an Algebraic Expression for These Situations
converting i inches into feet
the cost for tickets if you purchase 5 adult tickets at x dollars each
i / 12 5x

16. Write an Algebraic Expression for These Situations
the total cost for 5 adult tickets at x dollars each and 3 children’s tickets at y dollars each.
5x + 3y