Adding and Subtracting Integers Unit Grade 7 Math 5 Days Tools ...

Lesson: Day Four-Using Algebra Tiles to subtract integers and students sharing rules thatthey have discovered on adding and subtracting integersTime: 45 minutesObjectives:• Students will be able to subtract positive integers from positive integers.• Students will be able to subtract negative integers from negative integers.• Students will be able to subtract positive integers from negative integers.• Students will be able to subtract negative integers from positive integers.• Students will be able to discover the rules for adding and subtracting integers anduse them in real life context.Materials:• Class set of Algebra tiles• Overhead algebra tiles• Chart paper and markers—from last class to continue rules• Red and green crayons or markers• Subtracting Integers using Algebra Tiles--WorksheetActivities:1. On the board will be the following problem of the Day, for the students tocomplete as they sit down (5 min).• The temperature at 8pm was -6 degrees by 11pm the temperaturehad dropped 12 degrees. What was the temperature at 11pm?• Go over the different strategies your class tried to solve thisproblem.2. Pass out the algebra tiles the Exploring Integer Multiplication Worksheet.3. I will model how to do question #1, for subtracting integers.• We do not use the mat since we need to take away integers. I willplace six red integers in my workspace, than I will take away 2 redintegers leaving me with four red integers. Therefore -6 – (-2) = -4.4. I will model question #2.• I will place 2 green integers on my workspace. I need to remove 5green integers. I do not have 5 green integers. I will ask the classif I can do anything to get more green integers. That's right I canadd zero pairs to get green integers, because adding zero to anumber will not change its value. I will add one green and one redinteger to my workspace. I will have to add two more sets of zeropairs to have enough green integers to remove. Now I can takeaway 5 green integers. What is left on my workspace is 3 redintegers. Therefore 2 – 5 = -3.5. Have the Students answer questions 3-6 using their algebra tiles.16