Welcome to Math 112 Class #3 9/17/14 Please turn in HW #2 worksheets and Sample Test #1 stapled together! Make sure your name and “HW #2” is on the top!

WARMUP: Review for Test #1 5. Shaunice has 36 feet of fence to put around her rectangular flowerbed. How long and how wide will the flowerbed have to be so that she has 72 square feet of area to plant flowers?

Tonight’s Agenda Warm-up Go over HW questions Test #1 The Centauri Challenge Algebra tiles Adding & subtracting integers

Just for today, no matter where I am going, or what I am doing, or who I am doing it with, it is my intention to focus on the positive. Lucy MacDonald

Last week’s focus: Math practice #1 Make sense of problems and persevere in solving them.

Persevere Continue in a course of action even in the face of difficulty or with little or no prospect of success

Test #1 No calculators! This is an individual test! Work on “The Centauri Challenge” when finished. Break will be at ___________

New teams! Each index card has a letter on it – A, B, C, or D Each team must have person A, person B, person C, and person D. Stand up and find a new team. You cannot sit with any of the same people!!!! Once you find your team, discuss the Centauri Challenge problem!

The Centauri Challenge

PQRSSQR -------- RQ Any 2 letters can be switched (PQ = QP) If ending is 2 same letters, replace 2 letters with Q (RSS = RQ) If beginning is 2 same letters, add S in front (PPR = SPPR) If start and finish is same letter, put an R in place of all the middle letters (PQRSP = PRP)

Icebreaker – Textbook p. 5 This is from CC3, problem 1-2. After doing the ice breaker, debrief with explanation of the importance of establishing good team norms, including making students feel comfortable working in teams.

Now look at this problem! (P. 7 #1-6) Discuss with your team.

HW #1 – You received 1 point for signing up for the Newsflash on my website and 4 points for answering the questions about the article EVERYONE CAN LEARN MATH AT THE HIGHEST LEVELS!!!! Believe in yourself! There is no such thing as a “math” person. Everyone can reach the highest levels they want to, with hard work.

Tonight’s focus: Math practice #4 Model with mathematics

Operations with Integers Four math operations: Add, subtract, multiply, divide Integers: . . . -4, -3, -2, -1, 0, 1, 2, 3, 4, . . .

Addition and Subtraction of Integers using Algebra tiles Each pair gets a small bag of tiles. Pull out small blue squares and small red squares.

2.1.3 What does “minus” mean? (P. 47) 2-22 What does “-” mean? Find as many ways to describe this symbol and discuss how these descriptions differ from one another.

2-23 Using an Expression Mat “Minus” can also be represented with a new tool called an expression mat, see first diagram below. An expression mat is an organizing tool that will be used to represent expressions. Notice that there is a positive region at the top and a negative (or “opposite”) region at the bottom.

The value -3 can be shown in two ways. Try to find both ways!

What do you think the value of this will be? = +

5 - 2

5 + (-2)

Are the values of these two expressions the same? 5 – 2 5 + -2 2 and -2 are called opposites

3 – (-5)

(-3) + (-5)

(-3) - (-5)

1 + (-5)

1 - (-5)

-1 - (-5)

2 + (-2)

Examples: 4 + -1 -3 + -2 -3 + 3 1 + -4 16 + -8 -25 + -30 -40 + 22

Remember – subtract means “add the opposite” 4 – 3 is the same as 4 + -3 Remember – subtract means “add the opposite”

Examples: 5 – (-2) -3 – (-2) -3 - 3 1 – (-4) 16 – (-8) -25 – (-30) -40 - 22

Homework #3 Textbook: Chapter 1 #1-4, 1-5, 1-9, 1-10, 1-11, 1-12, 1-13 Bring graphing calculator (if you have one)!