1-1 Variables That stuff that varies…

How much can I make at $6.00 an hour? Hours WorkedTotal Pay Earned What is the relationship between hours worked and total pay earned?

Variable Vocab: Variable – letter used to represent one or more numbers Values of the variable – numbers that can replace the variable Variable expression – expression that contains a variable Numerical expression (or numeral) – an expression that names a specific number

Multiplication Confusion??? X vs. * vs. nothing

Equal symbol Two different EXPRESSIONS can say the same thing: But,

Substitution Principle- an expression can be replaced by another expression of the same value (4  2) 12  (4 + 2) (3 + 2)  (6 – 1) Evaluate each expression when m = 1 and n = 2. 3(n + 4) (mn) + 4

1-2 Grouping Symbols Grouping Symbol - device used to enclose an expression that should be simplified first. Parentheses 6(5 – 2) Bracket 3[9 + 2] Fraction Bar

Order of Operations PPleaseParentheses EExcuseExponents MMyMultiplication DDearDivision AAuntAddition SSallySubtraction 1.Start with innermost grouping symbol and work your way out. 2.Do all multiplication and division from left to right. 3.Do all addition and subtraction from left to right.

Board Examples: Find the value of each expression. a. 5(8 + 3) b. 5(8) + 3 c. d. 10 – [10  (8 – 3)] e  2  4 f. Find the value of the expression when a = 4, b = 7, and c = 10

Assignment: 2 Dittos