1. Match each word to the correct definition.
Warm-Up
Match each word to the correct definition.
Each part of an expression
separated by an operation.
B. A number that stands by itself
C. A number that does not stand by itself (it is attached to a variable)
A letter that stands for a
particular numerical value
E. A number sentence without an equal sign, has at least two terms and one operation
Algebraic Expression
2. Coefficient
3. Constant
4. Term
5. Variable

2. 1-1 Variables and Expressions
You would be wise to listen carefully and take notes!
Goal: to write algebraic expressions
Algebra 1 Honors Ms. Register

3. mathematical quantity - anything that can be measured
or counted.
numerical expression – expression that represents a particular number
Example:
algebraic expression - consists of one or more constants and variables along with one or more arithmetic operations.
Example of an algebraic expression: 3x + 2
constants - numbers
variables - letters
operations - addition, subtraction, multiplication and division

4. Multiplication – use a dot or parentheses
Here are some ways to represent the product of x and y.
Use good form in an answer!
factors - the quantities being multiplied
Product – the result

5. Writing Algebraic Expressions
In English there is a difference between a phrase and a sentence. In math, Phrases  expressions. Sentences equations or inequalities.
Phrase
The sum of 6 and a number
6 + n
Sentence
The difference of a number and three is five.
n – 3 = 5
Sentence
Seven times a number is less than 50.
7n < 50
When choosing a variable for an unknown, it may be helpful to select a letter that relates to the unknown value (for example: let a represent age). If a variable is given use it!
Sentences must have a verb!
Sentences must have a verb!

6. Would you say 5 notebooks or notebooks 5?
The product of five and a number 5n
The product of a number and five
Would you say 5 notebooks or notebooks 5? 5n
Write your answer in good form - the number comes before a variable in a term involving multiplication.

7. Use a fraction bar to designate division!
Write an algebraic expression for each word phrase.
a. The difference of a number and 7
n – 7
b. 32 increased by a number
32 + n
c. 25 less than a number 25 n –
d. 10 less the product of 5 and a number
10 – 5n
e. The quotient of a number and six. n 6
Use a fraction bar to designate division!

8. Did you use a fraction bar to designate division?
Example 1 Write the phrase as an algebraic expression.
a. 11 greater than a number
Did you use a fraction bar to designate division?
n + 11
b. a number subtracted from 15
15 – n
c. The sum of a number and 30
n + 30
d. Maria’s age minus 27
a – 27 18 n
e. The quotient of 18 and a number
f. The sum of a number and ten, divided by two.

9. Which of the following expressions represents 7 times a number decreased by 13?
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10. Which one of the following expressions represents 28 less than three times a number?
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11. Write a verbal expression for: 1) 8 + a.
The sum of 8 and a 2)
The ratio of m to r
Do you have a different way of writing these?

12. Which of the following verbal expressions represents 2x + 9?
twice a number increased by 9
a number increased by nine
twice a number decreased by 9
9 less than twice a number
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13. Which of the following expressions represents the sum of 16 and five times a number?
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