1. 1 1-6 Solving Equations by Adding & Subtracting Aim: Aim: How can we write and solve equations using addition and subtraction? CCSS: 6.EE.7

2. 2 Aim: Aim: How can we write and solve equations using addition and subtraction? Warm up Vocabulary Review: A ____________________ to an equation is any value that makes the equation true. Simplify each expression. 1. 6 + (-4) 2. -15 + (-7) 3. 20 - (-5) 4. -27 - 9

3. 3 The Addition Property of Equality If you add the same number to each side of an equation, the two sides remain equal. 10 = 5(2), so 10 + 3 = 5(2) + 3 21 = 3(7), so 21 + 9 = 3(7) + 9

4. 4 The Subtraction Property of Equality If you subtract the same number from each side of an equation, the two sides remain equal. 10 = 5(2), so 10 - 3 = 5(2) - 3 32 = 4(8), so 32 - 10 = 4(8) - 10

5. 5 Solving by Adding Solve for k and r: -2 = k - 14 r - 32 = -5

6. 6 Solving by Subtracting Solve for q and z: 24 + q = 100 z + 45 = -65

7. 7 Which Strategy Do we Use? An airplane climbs a height of 7,900 ft during a flight. At that moment, the airplane’s altitude is at 13,220 ft. What was the airplane’s original altitude? (HINT:) First write the equation that can represent this situation.

8. 8 Think, Turn & Talk 1. Vocabulary Check: How is an expression different from an equation? 2. Your friend made y bracelets. After she gave away 4 of them, she had eight bracelets left. Write an equation to model the situation. Use Mental Math: Find whether -3 is a solution. 3. a + 4 = 7 4. w - 7 = -10 5. -1 + c = 4 6. z - 3 = 0 7. 7 + p = 4

9. 9 Activity Lab: Number Square A number square is a square table with the same number of rows and columns. Each row, column and main diagonal in the square has the same sum. Example: The following Number Square has the sum of 15 in every row, column and diagonal. Number Square of 15 834 159 672

10. 10 Complete the Number Square   Task: Write and solve an equation to find each missing value in the Number Square below.   Step One: Use a row, column or diagonal with no variables to find the sum.   Step Two: Use the same sum to write an equation for all the other possible sums with variables. 10 2b-2 ac 01-4

11. 11 Exit Ticket A small separate piece of paper. Solve each equation for the given variable. (Hand In) 1. w - 2.45 = 3.1 2. h - (-7) = 4.3 3. -12 = -6.4 + m 4. -95 = b + (-100)