Distance Education Mini-Lesson, Module 5 Mary C. Fanchette TEC 571 Grand Canyon University Instructor: March 23, 2011

Objective: TLWBAT solve algebraic addition and subtraction equations by applying the inverse operation and substitution to check solutions. Standard: Use inverse operations to solve one-step equations that have whole-number solutions and variables with whole-number coefficients. What: Solve addition and subtraction equations Why: To find the unknown value and to master the foundation skills for Algebra How: Using inverse operations and substitution to check solutions

Let's Think! When you were in elementary school, you learned about things called "fact families". Can you still find the missing members of these "fact families"? 1. _____ + 7 = _____ - 5 = 3 3. _____ x 8 = _____ ÷ 4 = 3

Deeper Thinking.... Can you solve these? 1. x + 7 = n - 5 = 3 3. m x 8 = s ÷ 4 = 3 Do they look similar to the "Fact Families" that you just solved? What do you think the letters represent?

Algebra: a language of symbols, including variables.

Variables - Review variable - a letter that stands for a number 6 + m = 13 7t = ÷ p = 9 z - 8 =3

Words to know: Equation: a mathematical statement that has numbers, at least one variable, and an equals sign. An equation is balanced, like a scale. Evaluate: To solve, to find the value of Inverse operations: Operations that undo each other, opposite: addition/subtraction, multiplication/division Solution: the value of a variable that makes the equation true or balanced.

Algebra Equation Inverse Choose the best term from the list to complete each sentence. 1. An ________ has numbers, variables, an equal sign and at least one operation. 2. Operations that "undo" each other are called ________________________. 3. _____________ is a language of symbols, including variables. Are you ready?

Inverse Operations 1. What is the inverse of multiplication? 2. What is the inverse of subtraction? 3. What is the inverse of addition? 4. What is the inverse of division?

Solving Addition and Subtraction Equations

The "How To" for solving equations: 1. Identify the operation taking place. 2. Solve by performing the inverse operation on both sides of the equal sign to keep the equation balanced. 3. Check your answer by substituting the value you found in the place of the variable.

A Question of Balance The two sides of an equation are equal to each other. The left side and the right side must be balanced. When you do something to one side of an equation, you have to do the same thing to the other side = 10

Quick Video to help out... /studyjams/jams/math/algebra/a dd-sub-equations.htm /studyjams/jams/math/algebra/a dd-sub-equations.htm

Together… We Do! 1) k + 24 = 45 2) n - 15 = 40 3) 4 = x ) 10 = y + 6 5) 7 + n = 18 6) t - 9 = 23

On Your Own… You Do! 1) 21 + x = 63 2) s - 7 = 12 3) a + 6 = 11 4) 24 = y -13 5) m - 5 = 16 6) 100 = w + 75

Checking for Understanding… Let's see if you can answer some questions about algebra and equations.... Number your whiteboards 1-5.