1. Symbols and Expressions 1-1

2. I. Algebraic Expressions  Vocabulary: 1. Variable – letter that represents one or more numbers 2. Algebraic expression – an expression that contains at least 1 variable 3. Evaluate – substituting a number for each variable and calculate 4. Natural numbers – numbers used for counting (1, 2, 3, and so on) 5. Whole numbers – natural numbers and zero (0, 1, 2,and so on) 6. Rational numbers – set of numbers that include natural and whole numbers

3. II. Order of Operations  The order in which we solve all math expressions Please- Parentheses (and all other grouping symbols) Excuse- Exponents My Dear-Multiplication, Division (left to right) Aunt Sally-Addition, Subtraction (left to right)

4. 7  2 + [7 + 3(5 – 2)] ÷ 4  2 7  2 + [7 + 3(3)] ÷ 4  2 7  2 + [7 + 9] ÷ 4  2 7  2 + 16 ÷ 4  2 14 + 16 ÷ 4  2 14 + 4  2 14 + 8 22

5. Examples: 1. 36 ÷ (4 + 5)2. 24 – (12 + 3) ÷ 53. 4 + 6 2  1

6. III. Evaluating  Substitute the given number for the variables listed  You cannot evaluate without being given the value  Once you substitute the values into the problem, solve using the order of operations t + 3 + t for t = 4 4 + 3 + 4 7 + 4 11

7. Examples: 1. 14 – (b + 5) for b = 32. s(t – 4) for s = 4, t = 83. x + 5 for x = 7 2  3