1. Algebraic Expressions
Notes
7th Grade

2. Algebraic Expression ordinary numbers variables (like x or y)
An Algebraic Expression is a mathematical phrase that can contain:
ordinary numbers
variables (like x or y)
operators (addition, subtraction multiplication and division)

3. Variables, operators and expressions
A variable is a letter that stands for a missing number.
An operator is add, subtract, multiply or divide.
An expression puts variables together with operators.

4. a + 1 a - b 3 x x - a / b Examples: A number plus one
The difference between “a” and “b”
The product of three and a number
A number “a” divided by a number “b” less than a number “x”

5. Key Words Addition increased by more than combined total of sum
added to

6. Key Words Subtraction less than fewer than reduced by decreased by
difference

7. Key Words Multiplication of w ( t ) times ( w ) ( t ) multiplied by

8. Key words
Division
per a
out of
ratio of
quotient of ÷

9. Phrase to Expression nine increased by a number x 9 + x
fourteen decreased by a number p
14 - p
seven less than a number t
t - 7
the product of 9 and a number n
9 · n or 9n
thirty-two divided by a number y
32 ÷ y or

10. The use of “than”
Whatever comes after the word “than” ALWAYS goes first!
a number less than 5
5 - b
a number more than 7
7 + n

11. Practice Fifteen less than twice a number
Three times a number, increased by seventeen
The product of nine and a number, decreased by six
30 + 7n
4/a - 5
Jenny earns $30 a day working part time at a supermarket. Write an algebraic expression to represent the amount of money she will earn in “d” days.

12. Answers 2a - 15 3a + 17 9a - 6 Seven times a number more than 30
Five less than four divided a number
30d

13. Vocabulary & Essential Question
Complete the Frayer Model for each word.
Variable
Ratio
Proportion
Algebraic Expression
Equation
Essential Question:
How is an algebraic equation like a balance?