Number Theory Lesson 15 Variables and Algebraic Expressions Ms. Drake 7th grade Math Number Theory Lesson 15 Variables and Algebraic Expressions

Week by Week Essentials Week 4

Number Theory Addition Property of Equality Algebraic Expression Base Coefficient Composite Number Constant Division Property of Equality Equation

Number Theory Evaluate Exponent Greatest Common Factor (GFC) Inverse Operations Isolate the Variable Least Common Multiple (LCM) Like Terms

Number Theory Multiple Multiplication Property of Equality Numerical Expression Order of Operations Power Prime Factorization Prime Number Scientific Notation Solution

Number Theory Solve Standard Form Subtraction Property Of Equality Term Variable Verbal Expression

Variables and Algebraic Expressions Algebraic Expression: an expression that contains at least one variable. Example: 3 + x 5(b-2)

Variables and Algebraic Expressions Evaluate: to find the value of a numerical or algebraic expression.

Variables and Algebraic Expressions Constant: stays the same A value that does not change. 2 always represents the value 2 5 always represents the value 5

What are examples of quantities that are constant? The year you were born… The number of hours in a day…

Variables and Algebraic Expressions Variable: varies- is not the same A letter that takes the place of an unknown number or numbers. A symbol used to represent a quantity that can change.

What are some examples of quantities that vary? The price of gasoline… Temperatures….

How can we find out how much money Abdul could help raise Abdul entered a walk-a-thon for a local charity. His sponsor provided the $20 entry fee and will provide $4 for each mile he walks. How can we find out how much money Abdul could help raise

Make a table to display the information How would we write the expression if the number of miles walked is replaced by the variable m?

If Abdul walked 13 miles, how much would he earn for charity? Miles Walked Expression Amount 1 20 + 4(1) 24 5 20 + 4(5) 40 If Abdul walked 13 miles, how much would he earn for charity?

What if Abdul wanted to earn $100 for charity What if Abdul wanted to earn $100 for charity? How many miles must he walk?

Evaluate each expressions for the given value of the variable. 3x – 2 for x = 5 … for x = 7

28

Evaluate an algebraic expression with two variables.

…Until next time solve this magic square with a partner …Until next time solve this magic square with a partner. In a magic square each row, column and diagonal will have the same sum.

Evaluate for x = 4 x = 6 and x = 0. Which solutions are true?

This is a magic square only if after you solve each expression, the sums of the solutions in each row, column and diagonal are the same.

24 7+4 11 4 2(4)+1 9 4+2 6 0.5(4)+6 8 4+6 10 3(4)-5 7 3(4) 12 4+1 5 24 24 24 24 24 24 24

Six is not a solution. 35 6+6 12 6 2(6)+1 13 6+2 8 0.5(6)+6 9 3(6)-5 3(6) 18 6+1 7 31 29 38 33 33 32 28

Zero is not a solution 2 7+0 7 2(0)+1 1 0+2 6 0.5(0)+6 0+6 3(0)-5 -5 3(0) 0+1 8 24 -4 8 6 8 14