1. Solve and Write Addition Equations How do you determine if two numbers or expressions are equal?

2. Vocabulary A lot of you have been using mental math to solve these equations. Another way is to use INVERSE OPERATIONS, which undo each. For example, to solve an addition equation, use subtraction.

3. Using the inverse operation 8 = x + 3 -3 = - 3 5 = x

4. Solve each equations C + 2 = 5 6 = x + 5 3.5 + y = 12.75

5. Subtraction Property of Equality If you subtract the same number from each side of an equation, the two sides remain equal.

6. Subtraction Property of equality 5 = 5 -3 = -3 2 = 2 x + 2 = 3 - 2 = -2 X = 1

7. Solve each equation y + 7 = 2210 = 6 + e A board that measures 19.5 meters in length is cut into two pieces. One piece measures 7.2 meters. Write and solve an equation to find the length of the other piece.

8. Solve the equation It takes 43 facial muscles to frown. This is 26 more muscles than it takes to smile. Write and solve an equation to find the number of muscles it takes to smile.

9. BRAIN BREAK With a partner - play human rock paper scissors.

10. Word problem Frank and George have 245.5 downloaded minutes of music. If Frank has 132 minutes, how many belong to George? Write and solve an addition equation to find how many minutes belong to George.

11. J.T. and Brad have read a total of 1,254 pages last month. If J.T. read 555 of those pages, how many pages has Brad read? Set up an addition equation to represent this, then solve.

12. A male gorilla weighs 379 pounds on average. This is 181 pounds more than the weigh of the average female gorilla. Write and solve an addition equation to find the weight of an average female gorilla.

13. Solve each equation – Check your solution by putting back into the original problem. c + 1/3 = 4/5 9.34 = 2.1 + s 7.1 + a = 9

14. Addition Equations Zach and Paul together have $756.80. If Zach has $489.50, how much does Paul have? Write and solve an addition equation to find how much money belongs to Paul.

15. Addition Equation The average length of a King Cobra is 118 inches, which is 22 inches longer than a Black Mamba. Write and solve an addition equation to find the average length of a Black Mamba.