2. ALGEBRA

3. VARIABLES AND EXPRESSIONS
Algebra – Uses symbols to represent quantities that are unknown or that vary. You can represent mathematical phrases and real-world relationships using symbols and operations.
Quantity – Anything that can be measured or counted.
Variable – a symbol usually a letter that represents a value.

4. VARIABLE AND EXPRESSION
Numerical Expression – a mathematical phrase involving numbers and operations symbols, but no variables.
Example: = 5

5. VARIABLE AND EXPRESSION
Algebraic expression – When variables are combined with symbols.
Example x + 5
The expression x + 5 equals different values.

6. N + 5 X - 11 3m + - × ÷ Operation Word Phrases Expression 𝑎 7 or a ÷ 7
A number plus 5
Add 5 to a number
Sum of a number and 5
5 more than a number
A number increased by 5
N + 5 -
A number minus 11
Subtract 11 from a number
Difference of a number and 11
11 less than a number
A number decreased by 11
X less a number 11
X - 11 ×
3 times a number
3 multiplied by a number
Product of 3 and a number 3m ÷
A number divided by 7
7 divided into a number
Quotient of a number and 7
𝑎 or a ÷ 7

7. EXAMPLE 1 – WRITING EXPRESSIONS WITH ADDITION AND SUBTRACTION
What is an algebraic expression for the word phrase?
32 more than a number n
58 less a number n

8. EXAMPLE 2 – WRITING EXPRESSIONS WITH MULTIPLICATION AND DIVISION
What is an algebraic expression for the word phrase?
8 times a number n
b) The quotient of a number n and 5

9. EXAMPLE 3 – WRITING EXPRESSIONS WITH TWO OPERATIONS
What is an algebraic expression for the word phrase?
3 more than twice a number x
9 less than the quotient of 6 and a number x
The product of 4 and the sum of a number x and 7

10. EXAMPLE 4 – USING WORDS FOR AN EXPRESSION
What word phrase can you use to represent the algebraic expression 3x ?
Expression x
Word Phrase three times a number x or
the product of 3 and a number x

11. EXAMPLE 5 – Writing a Rule to Describe a Pattern