1. Algebraic Expressions Intro to Algebra

2. Numerical Expression A numerical expression represents one value and can contain one or more numbers and operations. 4 + 5 is a numerical expression. It represents the value 9.

3. Example Which numerical expressions represent a value of 21? a)9 + 24b) 4 + 7 + 14 c) 9 + 4 + 10 d) 7 x 3e) 5 + 2 x 2 - 1 f) 160 ÷ 8

4. What if they are not numbers? 7 + x 4y + 3 8 – y ÷ 2

5. Variables A variable is a symbol that can represent different values. We can substitute numbers in for variables to give the expression a value.

6. A Number next to a Variable What does it mean when a number is written next to a variable? 4x it means to multiply. 4x means 4 times x.

7. Examples

8. Evaluating more expressions 1.p + 11 – q (when q = 16, p = 32) 2.1 ÷ x · y (when y = 4, x = 1) 3. 14 + b · c (when b = 2, c = 3)

9. Algebraic Expression An algebraic expression contains variables, numbers and operations. The value of an algebraic expression can change.

10. Parts of an Algebraic Expression Terms – A term can be a constant, a variable, or a number with a variable. Terms are separated by either a + or a – sign. Coefficient – In a single term containing a number and a variable, the number in front of the variable is called the coefficient.

11. Creating Algebraic Expressions Create an algebraic expression to represent the following statements. 1. 5 more than a number. 2. 17 less than a number.

14. Remember… Does order matter in addition and/or subtraction? Subtraction only

15. A word to be careful with… Less than Order is opposite

16. Create an Algebraic Expression 1.Andy had 14 pencils, but then he lost some. 2. Jake had a number of baseball cards, and then he got 24 more. 3. Diane reduced the number of calories she ate by 50.