300 likes | 620 Views
Transparency 2. Click the mouse button or press the Space Bar to display the answers. Splash Screen. Example 2-1b. Objective. Evaluate expressions and identify properties. Example 2-1b. Vocabulary. Variable. A symbol, usually a letter, used to represent a number x a y. Example 2-1b.
E N D
Transparency 2 Click the mouse button or press the Space Bar to display the answers.
Example 2-1b Objective Evaluate expressions and identify properties
Example 2-1b Vocabulary Variable A symbol, usually a letter, used to represent a number x a y
Example 2-1b Vocabulary Algebraic expression An expression that contains a variable, a number, and at least one operation symbol 4n x - 3
Example 2-1b Vocabulary Numerical expression An expression that contains numbers and at least one operation 3 + 4 7 – 6 6 + 4 - 3
Example 2-1b Vocabulary evaluate To find the numerical value of the expression
Example 2-1b Vocabulary powers Numbers written using exponents 43 82
Example 2-1b Vocabulary equation A mathematical sentence that contains an equal sign (=) 3 + 4 = 7 X - 4 = 8
Example 2-1b Vocabulary Open sentence An equation that contains a variable 2x - 4 = 12
Example 2-1b Vocabulary property An open sentence that is true for any numbers
Example 2-1b Vocabulary counterexample A statement or example that shows a conjecture is false
Example 2-1b Vocabulary Order of operations A set of rules to evaluate expressions
Example 2-1b Order of Operations Rules • 1. Do all operations within grouping symbols first. • ( ) [ ] { } • 2. Evaluate all powers before other operations. • exponents 32 square roots 16 • 3. Multiply and divide in order from left to right. • x 3(4) • Add and subtract in order from left to right. • + - P E MD AS Please Excuse My Dear Aunt Sally
Lesson 2 Contents Example 1Evaluate a Numerical Expression Example 2Evaluate Algebraic Expressions Example 3Evaluate Algebraic Expressions
Evaluate Example 2-1a 3 + 9 - 2 ( 8 2 ) Write problem Follow the rules of Order of Operations 3 + 9 - 2 4 P E MD AS 3 + 9 - 2 Work inside parenthesis first Bring down 3 + 9 - 2 Divide 8 by 2 1/4
Evaluate Example 2-1a Follow the rules of Order of Operations 3 + 9 - 2 4 P E MD AS Multiply before adding and subtracting 3 + 9 - 3 + 9 - 8 Bring down 3 + 9 - Multiply 2 4 1/4
Evaluate Example 2-1a 3 + 9 - 8 Follow the rules of Order of Operations P E MD AS 12 12 - 8 Add and subtract from left to right Add 3 + 9 4 Bring down - 8 Subtract 12 - 8 Answer: 4 1/4
Evaluate Example 2-1b Answer: 2 1/3
Evaluate the expression Example 2-2a 3r + 2s - 4 Write problem 3(6) 3(6) + 2(3) 3(6) + 2(3) - 4 Replace r with 6 Replace s with 3 Bring down - 4 2/3
Evaluate the expression Example 2-2a Follow the rules of Order of Operations P E MD AS 3(6) + 2(3) - 4 Multiply before adding and subtracting Multiply 3(6) 18 18 + 18 + 6 18 + 6 - 4 Bring down + Multiply 2(3) Bring down - 4 2/3
Evaluate the expression Example 2-2a 18 + 6 - 4 Follow the rules of Order of Operations P E MD AS 24 24 - 4 Add and subtract from left to right Add 18 + 6 20 Bring down - 4 Subtract 24 - 4 Answer: 20 2/3
Evaluate the expression Example 2-2b Answer: 24 2/3
Evaluate the expression Example 2-3a Write problem Replace q with 5 Replace r with 6 Bring down - 3 3/3
Evaluate the expression Example 2-3a Follow the rules of Order of Operations P E MD AS Remember: The fraction bar is a grouping symbol 30 . 18 18 - 3 Work in the numerator first Multiply 6(5) Now work in the denominator Multiply 3(6) Bring down - 3 3/3
Evaluate the expression Example 2-3a 30 . Follow the rules of Order of Operations 18 - 3 P E MD AS Finish working in the denominator 30 . 15 Bring down 30 . Subtract 18 - 3 2 Now use the fraction bar as division Divide 30 by 15 Answer: 2 3/3
Evaluate the expression Example 2-3b Answer: 2 3/3
End of Lesson 2 Assignment
Name the property shown by Example 2-4a Multiplying by 1 does not change the number. Answer: This is the Multiplicative Identity. 4/4
Name the property shown by the statement Example 2-4b Answer: Commutative Property of Multiplication 4/4