Transcript 8.24
On your sheet of paper… • Write down your daily steps to enter into the classroom. – Your list should include what your body is doing AND what your mouth is doing during your steps. Entering into the classroom • Greet Ms. Diehl at the door. • Silently grab your daily handouts from the back table. • Sharpen your two pencils. • You may check your outbox if you are expecting graded work, but you have to be sitting in your seat by the time the bell rings or you are considered tardy. • Silently begin working on your Do Now before class gets started. ON YOUR DESK: • HW on the right side • 1 sheet of paper for your Do Now on the desk. • Do Now: 1. -3 + 4 = 3. -9 + -9 = 2. -5 + 2 = 4. 5 + -3 = 5. How are negatives and positives the same? Answer Check 1. 2. 3. 4. -3 + 4 = -5 + 2 = -9 + -9 = 5 + -3 = 5. How are negative and positive numbers the same? • • • • 1 -3 -18 2 • Negative numbers are the opposite of positive numbers. What three tools did we learn yesterday? • Number line – Identify the starting point. – Adding or subtracting? – Moving to left or right? – How many spaces? • Holes and Hills – Holes are negative and hills are positive – How many match up and cancel out? • The Rules Which method did you use? Why do you like it the best? I can add AND subtract integers using a variety of tools! • Get out your notes from yesterday. Turn it over, and look at the back side. War! • • • • • • • Black Cards are negative Red cards are positive 1. Each person flips over two cards Jack = 11 at a time. 2. Add the cards you have. Queen = 12 3. Whomever has the biggest number wins and collects the pile of King = 13 cards. 4. You must write your problem in the Ace = 14 first box, work in the second, and answer in the third. YOU MUST Joker = 15 RECORD EACH TIME! 5. Your goal is to collect all the cards in the stack. 6. Play 3 games. GAME TIME! Two groups from yesterday join to make one large group of 4. If you were a group of 3 stay put and don’t join with anyone. 1 Deck of cards per team. Divide the deck of cards evenly between members. 4 team members = 13 each 3 team members = 17 or 18 each I can add AND subtract integers using a variety of tools Why? I can add AND subtract integers using a variety of tools. • Tools – Same Opposite Opposite – Counters – The Rule Think… • If negatives and positives are opposites…then what is the opposite of addition? – SUBTRACTION! • 8 and -8 • -6 and 6 • 4+9 4 -9 Subtracting Integers • Subtracting an integer is the same as adding its opposite. • How do we know which signs to change? Examples 1. 7 – 4 = 7 + (-4) 2. 12 – (-5) = 12 + 5 3. The temperate started off at -12 degrees in New York City. By the end of the day, the temperature fell another 3 degrees. 4. (-22) – (-40) = (-22) + 40 Re-write! • Re-write each equation to be an addition problem. Solve using your favorite method. Remember our strategies! • -9 -2 = • 15 - -4 = • -7 - -3 = I can add AND subtract integers using a variety of tools. Practice with Counters • You have a bag with blue and green counters. Green are positive, blue are negative. • Place the number of negative signs and the number of positive signs for each number you have. • Eliminate any pairs of negative and positives. • The number you have remaining is your answer. Solve these problems using your counters. 1. 2. 3. 4. 5. 6. 7. -4 – 9 = -3 - -8 = 5 – 10 = 10 - -5 = -4 - - 8 = 9 – 11 = -12 – 36 = 8. -5 – 9 = 9. 17 – 6 = 10. 0 - - 9 = 11. -4 – 0 = 12. 25 - -8 = Addition or subtraction? • Brenda had a balance of -$52 dollars in her bank account. The bank charged her $10 for overdrawing her account. What does her account balance look like? Write an equation to solve this problem? Solve showing all of your work. Addition or subtraction? • Greg went diving off the coast of Australia last summer. On one of his dives, he started at 120ft below sea level. Greg then descended another 70ft. How many feet below sea level was Greg? Write and equation to solve this problem. Solve and show all of your work!