1. Evaluating
Algebraic
Expressions

2. 5 + 84 Numerical 3x + 10 Algebraic Expressions
An expression is NOT an equation
because it DOES NOT have an equal sign.
There are 2 types of expressions.
Numerical
3x Algebraic
Notice there are no equal signs in these
expressions so they are not equations!

3. 5 times 3 plus 8 (5•3) + 8 Expressions
A numerical expression contains only
numbers and symbols and NO LETTERS.
5 times 3 plus 8
(5•3) + 8

4. An algebraic expression contains only numbers, symbols, and
Expressions
An algebraic expression contains
only numbers, symbols, and
variables. It is sometimes referred
to as a variable expression.
The product of 3 and x x
The sum of m and m + 8
The difference of r and r - 2

5. Expressions
What is a variable?
A variable represents an unknown value.
2) 10 – ?
1) 4 + x
4) 20
3) 5y
A variable can be any letter of the alphabet since it represents an unknown.

6. 5 • c or 5c 7 • t or 7t 6 • d or 6d Expressions
Word Phrases for multiplication are:
The product of 5 and a number c
Seven times a number t
6 multiplied by a number d
5 • c or 5c
7 • t or 7t
6 • d or 6d

7. Always write the variable AFTER the number.
Expressions
The Placement rule for multiplication is:
The product of 5 and a number c
Seven times a number t
6 multiplied by a number d
5 • c or 5c
Always write the variable AFTER the number.
7 • t or 7t
6 • d or 6d

8. m = 2 6 + m ? 6 + 2 8 Evaluate means to find the value of an
Expressions
Evaluate means to find the value of an
algebraic expression by substituting
numbers in for variables.
m = 2
6 + m ?
6 + 2 8

9. r = 3 7 + r ? 7 + 3 10 Evaluate means to find the value of an
Expressions
Evaluate means to find the value of an
algebraic expression by substituting
numbers in for variables.
r = 3
7 + r ?
7 + 3 10

10. Evaluate the variable expression when n = 6.
Expressions
Evaluate the variable expression when n = 6. 1) 2)
Evaluate just means solve by substitution.

11. Evaluate the variable expression when n = 6.
Expressions
Evaluate the variable expression when n = 6. 3) 4)
Evaluate just means solve by substitution.

12. Evaluate the algebraic expression when n = 8.
Expressions
Evaluate the algebraic expression when n = 8. 1) 2)

13. Evaluate the expression if a = 3 and b = 4.
Expressions
Evaluate the expression if a = 3 and b = 4. 1) 2)

14. Evaluate the expression if a = 3 and b = 4.
Expressions
Evaluate the expression if a = 3 and b = 4. 3) 4)

15. Evaluate the expression if x = 5 and y = 3.
Expressions
Evaluate the expression if x = 5 and y = 3. 2) 1)